What cables are you using for a hidden in wall clean look? I have B&W 802 D3s coming.

We used bulk #12 gauge stranded copper cable throughout most of the rooms on the first floor while our house was being built. We had to use "code" cables otherwise the house would have not passed the inspection for occupancy permit. I also put speaker terminals in certain spots on the walls where I expected the speakers/amplifiers to be placed. The "code" cables are somewhat rigid and are not as flexible as "normal" speaker cables but I figured a #12 gauge copper cable would do the job. I even put speaker terminals in a few places way up on the walls where I thought I might put surround speakers. Right now, I’m only using some of the terminals for a 2-channel set up. Bottom line is, make sure you check your local safety electrical code regulations just to avoid issues down the line, for example when you decide to sell the house, etc. As an FYI, you can look all this up by a trip to your local Home Depot (if in US). They even sell cables down to #2 gauge which look quite impressive....but there’s no way you can connect anything less than #10 gauge to any off-the-shelf connectors. Those #2 gauge wires look awesome by the way...

@mgould This is one link: http://www.bluejeanscable.com/articles/inwallrating.htm

Here are a few quotes from that link:
"The main purpose of NEC is to prevent hazards to human health and safety from wiring, and these fall primarily in a few categories: electrical shock, tendency to start or perpetuate a fire, and production of toxic fumes when exposed to fire."

"To classify the types of cables suitable for reducing these risks in various applications, the NEC provides a system of ratings of cables. An example would be CL3, or "Class 3," which many people recognize as an "in-wall" rating because of the labeling on the spools of speaker wire found at home improvement stores."

"A "plenum," under Article 100 of NEC, is "a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system." The most common "plenum" space one sees in a/v installations is a dropped ceiling space in a commercial building, being used as a ventilation return. Most residences do not have any significant plenum spaces, so this is rarely a consideration in a residential installation--but on occasion it can be. Plenum cables are required to have jackets and dielectrics which don't easily give off toxic fumes when burned--the reason being that a fire in one part of the building can, through the ventilation system, feed toxic fumes to the entire building."

...It is a good article if you are detail oriented.  And, it's always good to understand what is involved when you are "breaking the rules" (as in the electrical code etc). I have previously run speaker cables under the floor from an amp to speakers, but that was a long time ago in terms of where my knowledge is today. For a casual space, I'd run cables behind the scenes. For a critical listening set up: No way, out in the open and away from any other cables etc.

Is plenum rated that important for in wall speaker cables? 

@Vicweast   Thanks!  Haven't ever looked at the code or requirements, so that's good to know.

@bcowen  My understanding about "plenum rated" cables is that code has to do with a fire combusting the insulation and thereby creating toxic smoke. The AntiCables seem to not fall into that category, but they are not plenum rated nor are they designed for that. 

I'm using the AntiCables too, except they are run under the floor instead of in the wall.  There is an open entry way right between the speakers, so my options were to run the cables on top of the floor and put some kind of cable protector over them, or run them under.  Since it's a suspended floor, it was pretty easy to drill some small holes and push the non-jacketed AntiCables through them.  No spades or bananas, just the bare wire ends into the speakers and amp.  Works well.  I'm not sure if there are code requirements for "under the floor" installations as there are for in-wall applications, but since the cable is not enclosed by sheetrock and is hanging in free air underneath the floor rafters, I'm not too worried about it.

What is your first must-have journey to OZ : fine 2-channel music or multi-channel HT ?

If you are settled on in-wall speaker cables, they had better be specifically warranted as fire-rated and explicitly described as such. Otherwise you will most likely automatically void your property insurance, and that is a big, big, FUHBAR step.

The in-wall cable selection is largely more budget-friendly and an easy DIY project that is fine for HT applications, but most won’t match up to the performance capabilities of "normal" 2-channel cables you would put in a high-end 2-channel kit. A budget BELDEN off-the-reel bulk DIY cable compared to a NORDOST VALHALLA , is an extreme comparative. For me, I kept my OEM non-fire-rated NORDOSTs in my high-end 2-channel gear (primary music and direct-passthrough for LF and RF and CC kept out of the wall, but I buried in-wall BELDEN Fire-rated long-run DIY terminated cables with medium quality banana connectors for the surrounds and rears that keeps things neater there, but let’s remember that these are only artificially manufactured fill-in sound channels and less sensitive/critical accordingly) .

Choosing Bananas vs spades is strictly a mix of
(1) the preferred ease of connections of your electronics and to the speakers, and
(2) favouritism towards your personal connector preferences, and,
(2) the quality and build of the connectors themselves, and tempered by that relation to the cables themselves. It makes no sense to put high-end EICHMANN OCC copper bullets or similar top-end Rhodium or gold plated connectors on just cheap entry level cable and expect anything more than an avoidable wasteful drain on your wallet . Conversely, the cheap-as-you-can go stuff will firmly establish themselves as a weak link accordingly. Everything is built to a price-point, and the bottom-end stuff is invariably the cheapest heavy to oxidize inferior nickel-plated or brass available.

In my AV setup I use DH Labs bulk cable, which I terminated on 5-channel in-wall banana plug connectors at one end and also at the 5 speakers which are in-ceiling (I tinned those conductors). Running from the amp to the wall, I use the same cable. I did this for only one reason: to give me more flexibility in moving my AV rig so that I can get behind it periodically. Instead of adding this additional break in the speaker wire (reduces audio quality), in retrospect I would have preferred to have excess cable on the floor behind the rig (a single continuous length).

I tried using the same cable with my audio-only two channel system, but I really prefer the AntiCables (solid copper with minimal dialectic). I am likely to upgrade those (pretty damn good) cables to a heavy gauge soft-temper silver in over-sized dialectic. ...Neither of which you should run inside a wall.

All the reading I have done on speaker cables guides me to use bare un-terminated ends. There are several papers on this, including one that discusses the difficulty of getting a predictable connection when using any termination (versus bare wire). However, for metals that oxidize in a manner that degrades the connection, you should consider the best termination spades/etc you can get as long as they help in reducing the oxidation problem. I have come to understand that silver wire does not have that problem as it oxidizes, as the result is said to be equivalent in conductance (in contrast to the more typical copper).

However... I also like swapping out tube amps for listening sessions, which introduces the benefits of banana connectors (quick switch, less wear and tear on binding posts) on the amp end of speaker cables. Everything at a price, eh?