Subdoofus, you have several good choices in this price range, which I have listed in my order of preference.
Musical Fidelity A3 int. amp 85wpc ($1495 new)
Audio Analogue Puccini SE 50wpc ($995 new)
Creek 5350 75wpc ($? new)
These are all very clean sounding and very musical integrated amplifies that would sound particularly good with high efficiency speakers. You should be able to pick one up used for ~ $600. Check Audiogon, Audio Shopper, Audio Web, and area stores for used/demo equipment.
If you are willing to spend a little more, consider the Creek 5350SE. A bit more power and more refined.
If you would like to spend less than 1/2 for a great little amplifier, I have an Arcam 6 35wpc that I am selling to upgrade to separates. I am currently using this British "giant killer" with modestly efficient Vandersteen 2ce signatures. The combination is both powerful and musical. The amp also has two pair of 5 way binding posts, so you can bi-wire speakers if desired. You can youu the difference to buy more CD's or books if you need them. Drop me an e-mail if you are interested. I was a starving grad student once myself, but that's no reason to give up good music.
You don't hear much about Densen, but I have been extremely pleased with the performance of my Densen Beat Series B-100. A VERY nice sounding amp, and one which you hear very little about. It retails for around 1200-1300, but since they are somewhat unknown in the U.S., they tend to be difficult to re-sell and should be found used in your pricerange. I also own a Rega Mira which is a solid little beast (though not nearly as lucid as my Densen) that could probably be found used in your price range. Good luck.
Check out the charity auctions right here. There is an ASL (Antique Sound Labs) 5W/15W SET integrated - retails at $600, bids around $400 right now. Should be a great match. Or try one of the Bottlehead pre's with the ASL WAV-8's. You might also be happy with the Outlaw 1050 - and be ready for HT even if you don't want to set it up right now. Good luck!
Cambridge Audio makes good stuff--better than NAD. A sleeper brand, but prices for their stuff are reasonable. Try www.spearitsound.com for more info (no association).
Look at Roksan, Audio Analogue and Audio Refinement used.
I don't believe there is a "best." There are a few well built solid state integrated amps in that price range and they will vary more in power rating and features than in sound, (to me.) I own and have enjoyed 3 of them: Creek 4330R, Audio Refinement Complete, and Creek 5350SE. The 5350SE is beyond the price range. The ARC by YBA is wonderful as well and will be just barely at your price, used, if you are lucky. (I paid $850 for a demo.) The Creek 4330R is remote controlled, has a pre-out if you want to add a subwoofer later, and is much more powerful than its 35W rating. I have never heard the 4340. Look at the 4330. Save some dough and buy some more music. Study hard. Charlie
I just downsized my main system from a separate preamp and tube monoblock amps which retailed for about $4K to an Audio Refinement Complete integrated. While the ARC has not burned in yet, I am very impressed with it. The sonic differences between it and my old gear have no relationship to the difference in cost and would not be obvious unless you have very revealing speakers. However, if you are a student and listen mainly to rock, you may want to consider an NAD integrated. Not as refined as the ARC, but much cheaper.
I have owned Creek 4330R integrated amp.
It uses passive preamplifier part which has only attenuator, tape monitor and component switch. For the bucks this amp does more than you'll pay for it. You should probably have to have a good quality source with stable output voltage of about 2...3volts preferably with no negative feedback for its best performance. I've had it with Arcam Alpha 8 CD-player and I loved it. The better source you'll hook up the better sound you'll get -- no bounds!
I'd buy a Linn Majik integrated amp - compact, flexible and great sounding - you can definitely find one used for $500-550. -Kirk
If you have a high efficiency speaker, you should try the tube amplifier, within your budget, I know the Space-Tech Lab. products might match your requirement, just check "http://www.space-tech-lab.com" , they have a pre-owned equipment section, there list a lot of used equipments. But even their new equipment is selling with very low price, I have heard those equipments in their showroom, they sounds great , really liquid transparent, rich and warm.
If you go with used units, you can easily get the Puccini SE or AR Complete for $600-650. I got my Complete for $650 with remote last year and am very, very happy with it. Between the two, I think the AR has a little tighter bottom end, but that may system dependent. Both are excellent units and really fill a room with warm, clean, music. You can't go wrong.
Have you considered the Naim Nait 2? Wonderful little integrated, and don't let the "low" 20 wpc fool you; this thing can rock with the best. Fluid and dynamic.
Try and check out the Cambridge Audio a500 it a 65 wpc with 0.02 THD and toroidial pwr supply for 400. Its an integrated with a remote. Supposed to be a real beauty. They have it at audio advisor.