Which would be the best system that...

Let me see. If you're buying used, it greatly depends on what you find and what kind of deal you get, but for $6k you should be able to assemble a fine-sounding system. (1) If you can find them, the Meitner PA-6/6i preamp and MTR-101 monoblocs offer superb sound for the money (circa $1500/new circa $6k). (2) The Sony SCD-777ES now costs more used than just a couple of months ago. Used to be around $1500, now closer to $2k (new $2500). You get superb CD and SACD sound. Reviewers caution 300+ hours break-in time. (3) Speakers. Here I think personal taste and preferred music, if any, count for more than in the first two categories. I personally have long thought that Tannoy DMT studio monitors blow away everything else for the money. The System 15 DMT II doesn't come up that often on the used market, but prices seem to be around $2k (list around $4k). Or you can get System 12 for under $1k. There are many other possible speaker choices, though. And I hesitate to preach in this area for precisely the reasons mentioned above. Beside their unforgiving accuracy, superb resolution, fabulous dynamic range and transient response, the Tannoys, at 98 dB for the 15s and about 93 dB for the 12s, are sensitive enough that you could easily power them with tubes if you ever wanted to. Word is that Tannoy finds the DMT cabinets too expensive to build and will be switching to something more economical, so now's a good time. (4) Now this system, lacking admittedly a tuner and turntable, would total around $5500. (5) For another $500, you could easily pick up a used Thorens TD-125-II or TD-126-II/III with a quality arm plus a new quality MM cartridge like the Audio Technica AT-440ML or Reson Reca. (6) For cables and interconnects you could spend another couple of grand and go way over your budget, but I'd advise against it. Fiddle with cables after you've bought some delightful new music to enjoy on your system. For now get Markertek or someone to make up interconnects from Canare StarQuad microphone cable and Neutrik ProFi RCA connectors. For speaker cables, there's some good DIY options out there, but StarQuad speaker cables would do you well until you've recovered from the other expenses. Or you could wait to find some Museatex cryogenic interconnects and cables. They seem to come up on eBay fairly cheap, fairly regularly. Biwire the Tannoys, though. (7) Anyway, this used $6k system will basically give you a $20-30k system that will be very hard to beat. (8) For what it's worth, this is the direction I've gone in, after 25 years of enjoying hi fi. Best of luck and happy listening. dr.joe.

Well, let's start by saying that speakers should be of first concideration when starting a sytem, most always!!!...not components! The speakers are at least 40-50% of the sytems (minus room acoustics) sound quality, concideration wise. So, to start out recommending you matching components before recommending sepeakers, in my oppinion, is putting the cart before the horse!
My recommendation would be to use the 1/3 rule, and go find some speakers that would equate to about 1/3 of your toatal budget range, that seem to work for the music you like! Then,once you've narrowed down the choices, try to ask some people what kinda gear works best with em, that would fit into that price range to finish out the sytem!
Really, also, a lot has to do with what you listen to and how you listen. If you haven't noticed, every reviewer and every audiophile in general, all have different equipment!...different tasts, rooms, needs, etc. No system is the sytem to have for every senario at every price range...Food for thought. However, certain speakers do seem to do best mated with certain types of gear often. So this can, again, be more easily accertained when you figure out the speakers that will suit your particular needs! Speakers like dipolar ribon planer or Electro static spakers will cause you to have to sit down in one spot to listen! Dynamic Piston Driver speakers will be more room friendly for around the house listening...you must concider.
Also, chose your digital front end after concidering your source needs! (i.e, CD's, SACD's, DVDA's, etc...)
Things like DVD multi source players can offer some great sound overall from their mediums they handle, for the money. But, usually, these sacrifice a bit of dynamic contrast and weight compared to better separate dac/trans combo's!
After concidering you speaker choices, and room conciderations (size, accoustics, etc), SYTEM MATCHING will be the single most important factor in getting good sound with your speakers! It's all about BALANCE, and making your system compontents compliment each other and work as a team!..they gotta go well with each other!
However, all that being said, may I recommend a few USED EQUIPMENT system choices to concider for general wide varriety CD music listening purposes/dubties/conciderations, not factoring for tuners or Phono...(Also, figuring for Non Rap music listeners, bombastic bass junkieshere, or ear bleed loud practitioners...no offense, just assuming the audience here...). Also, no biamping or other trick measures concidered either.

... System 1)
speakers) Sonus Faber Electa Amators (used @ $2300 avrg)
preamp) Pass Lab's L solid state preamp (used @$1k avg
amp) Threshold T 200, 100w/ch Class A (used $1.5k)
CD trans) Theta Data Basic (used @$450)
DAC) Theta Pro Progeny Or MSB link III(used $300)
Cables) Harmonic Pro 11 spker wire (used 8ft/pr @$250)
newer Harmonic Truth Link/Audio Quest Python
($400 for 2 pair used interconnects)
Kimber Illuminti D60 digital cable ($125 used)

Sytem 2).....
Speakers) Thiel 2.3's (used at $2300'ish)
Preamp) Audio Research tube pre (like LS2,LS22,or LS7)
(better tubes required, all used @ $700-900)
Amp) Pass Labs X150 solid state ($2k used)
Digtal) Same as previous or some DVD player piece
Wires) Same as previous, or similar

System 3)...(more polite delicate hi-res system)
speakers) Magneplanner 1.6 (used $1400)
Amp) Audio Research VT100 tube amp(Used $2600)
preamp) Aud Research LS2,LS22,Or LS7 tube ($700-$1000)
Digital and cables) Above mentioned choices, or other

System 4.....(sleeper system!!!)
Speakers) Thiel 1.5's (with Sound Anchor stands)
Amp) Some high end tube integrated number with at least 50-60 watts! (Cary, C.J., Audio Research, etc.)
CD) Sony SCD777ES SACD player (used $1400)
Cables) Above mentioned choices (used, $7-800)
...AND WOW!...WAY TOO GOOD FOR THE PRICE RANGE!

Other nice considerations to consider that would fit into this price range to concider building sytems around (depending on bass needs and dynamic range) would be....
....1) Proac Response 1.5's (used $1700)
2) Audio Physic's Tempo III's ($1800 used)
3) B&W 804 nautilu's (used $2200)
4) NHT 3.3's (used $2200)
5) Celestion Kigstons (used $2200)
6) Apogee Mini Grands (used $2400)

Hello Bryan:

I am going to cut to the chase here and expand onto what the others have said here so far. But needless to say, for about $6K, you should be able to net a fine sounding system, no matter whether you are buying new or used. The difference being if you buy new, then you are buying equipment that is going to be representative to what is being offered at that price point today, whereas if you buy used, then whatever pieces you are buying used today could have very well been part of a $20K to $30K (or $35K) system a few years back. Although, these very pieces no longer represent what is considered "state-of-the-art" in audio today, these are still very good pieces whatsoever. Like the others that has responded before me, I am also an advocate and a proponent to buying used, but only when the situation calls for it. Otherwise, I am also open to buying new. But just like I said, that depends on what your particular needs and wants are, and where you are trying to head when you are assembling your system.

So, with that said then, let's take a look at a few systems here.

System # 1 (and that would be MY system):

Speakers -- KEF Reference 102 Speaker System w/KUBE Equalizer -- $900.00 in 1988 (but if they were purchased brand new today, they would retail for around $1,300.00).

Amplifier -- Adcom GFA-545 MkII (a "bipolar" design rated at 100 Watts Per Channel) -- $600.00 in 1991, but purchased used for $250.00.

Preamplifier -- Adcom GFP-750 Passive/Active Line Stage (but no phono) -- $1,250.00 (in my opinion, one of the "undisputed" values at its price point).

FM Tuner -- Magnum Dynalab FT-101 -- $590.00 (costs more used than it did when it was brand new, but then again, did you check the latest prices on the FT-101A?? And as a bonus, I can still have my FT-101 upgraded to an FT-101A later on).

CD Player/Changer -- JVC XL-M509TN -- $400.00 in 1994. This is all I have right now, but I am considering something else more serious than the JVC right now. I was and still looking at the Meridian 506.24. But now, my acquiring a Meridian 506.24 appears to be in jeapordy. Why?? Because now, with newer (and lower priced) 24 bit/96 khz. CD Players starting to crop up and hit the market (namely, the Rega Planet 2000 and the Arcam CD72...... $950.00 and $800.00 respectively), and with newer formats (DVD-A and SACD) coming up on the horizon, I now beginning to question the need to spend more than $1,000.00 on a CD Player. Especially now, when you can get an SACD Player for just $800.00 (namely, a Sony SCD-C333ES). So, unless I can get a used or demo Meridian 506.24 for about the same price as a brand new Rega Planet 2000 or Arcam CD72, the idea of acquiring the Meridian appears to be going by the wayside. Think of it now, when I can get an Arcam CD72 (a stiff chassis, build quality, a high quality transport, 24 bit/96 khz. dacs, upgradability, AND great sound on top of that?? For $800.00?!?!?!!!!!) for $800.00, then you can figure out which way I am leaning toward on the fence. Afterwards, I won't be making anymore "digital" purchases until either newer high resolution format is decided upon (DVD-A or SACD) or an affordable, high quality universal digital player finally hits the market.

Cassette Deck -- Nakamichi BX-300 -- $595.00 (in 1987).

Cables -- MITerminator 2 and 3 Interconnects -- $80.00 and $45.00 respectively (if purchased from Audio Advisor).

That would be one system you can start out with. Or, if I was buying an all new system today, and I was determined to go the "USED" route, then this would be the system I would hope to net when it is all said and done.

Speakers -- Vandersteen 3A Signatures -- $1,600.00 (used).

Power Amplifier -- McCormack Power Drive DNA-0.5 -- $800.00 (used).

Preamplifier -- McCormack TLC-1 Transparent Line Stage -- $600.00 (used).

CD Player -- Sony SCD-777ES -- $1,500.00 (used).

Cables -- MIT CVTerminator -- $750.00 (used).

Speakers Cables -- MIT MH-750 Shotgun "Bi-Wired" -- $550.00 (used).

Or still you can look at the other posters that has posted before me and take a hard look at some of their choices as well. They have some very good equipment choices listed here. But whatever route you take, just note that before you can get any enjoyment out of any of these systems listed (whether it be mines or the other two posters before me), just note that patience, room size, acoustics and proper system matching will all be BIG keys to netting an enjoyable system later on when your system is finally finished.

Good luck.

--Charles--

Hello again, Bryan:

Oh, I forgot to list in my OWN system, what speakers cables I am using. They are also the MITerminator 2 Speaker Cables. These are the "single wired" version. And they cost $120.00.

Sorry for the omission.

--Charles--