The current Wood Magazine (#196, March 2010) reviews benchtop planers in what I think is a very useful, fair and well-written article. It rates the DeWalt DW735 ($650) and Makita 202NB ($530) as Top Tool, and the Ridgid R4330 ($370) and Craftsman 21758 ($280) as Top Value. Good analysis of snipe, cleanness of cut, power, etc.
I have an old (grey) Ridgid TP1300 two-knife planer and love it, it is a real workhorse that I found on craigslist for $180. My local Home Depot (Apex) has a re-furbished three-knife Ridgid planer for $300--at half the price of the DeWalt, I would be picking it up if I didn't already have one!