Best Integrated for 400 dollars

Musical Fidelity 75 wpc X-A2 is more powerful than Creek. Sold for $700.00 new. Thus would be near the top of my list if you can find one. They usually sell in a couple of days. What Hi-Fi compared it to ~$1,600 X-A1000 and said it was BETTER.
It is a 2-box design with outboard power supply which sort of defeats the point of an imtegrated IMHO.

Gotta give the nod to the new NAD BEE

Second the Creek. Great sound for tiny $$$.

Spencer

Not sure how much power you want/need, but the NAD c370 is a great value around this price. A conservative 120wpc. If you don't need or want that kind of power the NAD 3020 is great too. At this price point NAD is tough to beat IMO.

I have not heard all the amps mentioned. I can give my two cents on the Denon, as I just recently picked up the pma2000. It is paired with a Sony 333es sacd and Dynaudio 52 spkrs. I run a Technics TT also. I find the phono stage of the Denon to be very clean, but I'll limit my remarks to the CD.

I find the pma2000 to be very detailed and dynamic. It drives the little Dynes very well. It has good presence and seems very spacious in the presentation. It has good control at all sound levels. The amp really sounds great.

Other things I determined are that it has accentuated something with the Dyn speakers, they like to be played at higher volume levels. The 2000 drives them well at lower sound levels, but I find myself turning it up louder now than before because it just sounds better ;-) I listen to alot of orchestral music and it really hits its stride there. It does acoustic strings and piano very well and voices are natural tho maybe a little thin.

Dislikes with the amp are... it lacks balanced pre-outs, unforgiveable in this class of amp imho. I also think the Dynes could use an amp that was a little 'warmer', tho I can't blame the amp for that.

If you find the Denon at $400, you could always try it, and unload it if it doesn't suit your system or taste.

Nad 320bee. Brand-spankin' new it's 400, and it's really quite qood, although it doesn't have a phono stage.

Arcam and Creek are way better than Cambridge and Denon. Creek is more lively like Naim. Arcam more button down sound. I thought uninvolving. But Creek does not have much power despite what the ads say.

If you're looking for new, try the new Rotel RA line integrateds, which have an incredibly musical sound: I heard the RA-01 driving a pair of Tetra louspeakers, and I can't stop thinking about it since! Great micro-dynamics and dynamics. I believe they've won some awards in Europe already. And a beautiful slim-line silver casing, IMO. The matching CD player and tuner are also quite killer, a friend of mine who works in a high-end shop took home the tuner, which he felt offered more bang for the buck than the Magnums.

I found a Myryad MI-120 on this site for $450. Incredible build, features and sound quality.

I'm using an 80's Sony "Legato" "ACT"(Ta-Ax6) int. amp to drive my Chorus 705's. It's an excellent amp. Another 80's Sony int. amp (Ta-Ax44)drives my daughter's Energy XL-15's. For the $ used, unbeatable. IMO, I would look into a warm sounding/refined int. amp to drive JM Lab spks. I would consider a Marantz PM-57 int. amp as well. A soft/mellow sounding int. amp which would mate well to the JM Labs. (I have mint one w/box, manual & remote. Send me an e-mail if you'd be interested.) Also, you'd might consider older (70's) Kenwood/Sansui int. amps as well. If I had to choose an int. amp on your list, I'd go w/the Arcam. (I know a dealer which has a very hard to find mint Arcam 5+ int. amp.) Good Luck. Bill

Used Rega Brio is quite musical, new NAD 3020 version (50wpc).