Here's my two cents on what to buy...
You'll want something for anatomy. Your two options are Moore/Dalley (Clinically Oriented) and Netter (Just a bunch of very detailed pictures). Everybody seems to feel that Netter is the way to go, but I like Moore/Dalley better-- there are some excellent charts, explinations, clinical correlations and its just a better overall reference in my opinion. Netter's drawings are much better than M/D, but you can find other pictures on the net or anatomical relationships in M/D that netter just doesn't spell out as well.
Big Robbin's for Pathology (Pathological Basis of Human Disease) is a definite must have.
Embryology text-- I would say buy this only if you haven't had embryo before, if it is the same text as us MS-IIs used (it was new lest year, so it should be the same) it came with a pretty useful CD.
Pharm-- I wouldn't recommend buying the Lange text
Micro-- WOULD recommend buying it, helps out a lot with lab and goes into more detail than BRS books
Histology/Cytology-- get a good picture guide. I (and others) had some problems at the start of the year. If you haven't had much histology in your past-- definitely buy one.
Immunology-- I'd get a BRS book
Physiology-- Won't need until a little later in the year, most people like Guyton.
BRS books-- Buy them All.. ask for them all as a gift, they are cheap and sum up everything VERY well. If you don't know yet, BRS= Board Review Series. They are very simple looking books, fairly small (1/2-3/4 inch thick) and pretty fairly priced.
There are some good medical dictionaries out there. My favorite is CancerWeb/OMD (online, UK based). I have 2 copies of Stedman's plus the school has it available online. I'm on CW at least 5 times a day... if you're on the net a lot, don't buy one and just use this link:
http://cancerweb.ncl.ac.uk/omd/
Other than that, you'll know what you want to buy as you go. My advice is stick to BRS books, Step-Up/First AID (USMLE rview books) when preparing for tests, and go to the full texts when trying to learn the material.
Stuff I wish I hadn't bought: you'll see me selling it at the start of the year.
Hope that helps