I am familiar with a fair range of these, as I have yet to transform my "wine room" into a single actually functioning cellar. If you are not looking for aesthetics (if you are, I'm of no help) lately I've been liking the models made by Danby. Their racks are rubber coated and do not damage the labels, and their cooling is relatively constant. (I haven't had them for that long, so I can't speak to their longevity.)
I buy them online and do a bit of shopping and price comparison (though, as recently reported in the NYT, online prices now change constantly); most recently I bought a 35 bottle unit from Home Depot for a little over $200 (including shipping).
I hope that's of some help,