for a flat bed scanner i have two reccomendation depending on what you want to scan.
epson 3200 (will do all negs up to 4x5 with the included adaptor) and if you get the pro package it includes some of the best imaging OCR software todate (silverfast) 300/500 for pro package
next would be epson 3170 is is sort of a modified version of the 3200 but still can do alot, its claim to fame is built in color correction around $200 (also id your looking for silverfast software for this model there isnt any because of modified USB controls and commands)
i have the 3170 and have access to the 3200 and i can tell you both are very good, if i was to do it over again i would get the 3200 pro as i could use the silverfast software for controlling the 3200. but since as it stand right now im shooting a high quanitity of film i may be looking a nikon coolscan 4000 or 8000, depending if i start to shoot, 120 or 220 films for school, but then i may just use the 3200 for the larger films, and getthe coolscan 4k to do my negative scans.
now if your going to be doing a high quanitity of negatives i would reccomend the nikon coolscan scanners, albet more pricey but the quality is there and highly controllable.
FWIW
Scubatooth