In reality, this really isn't that complicated of a situation, IMHO. I recommend only the Minolta or Nikon scanners, and the latter more than the former. In the $500-ish or less range, you therefore only have 2 options.
Your across-the-board options, then, are:
Minolta DS IV - if you're doing traditional B&W only. can't beat the price, but I recommend ICE if you're going to do any slide or c41 work.
Nikon V - This is the lowest end current scanner I'd get, personally. Try getting the film strip holder, which is apparently an option now (came standard on my IV).
Minolta 5400 II - this is like $650 or so, I think. People have had issues with it, esp. with the software and Vuescan's dust removal has gone back/forth, but still a good buy. It's not particularly fast, and the extra 1400 dpi above the Nikons is, in all honesty, not much of a practical difference. But if you want more than the V but can't afford the 5000, this is your bet.
Nikon 5000 - faster than the V. The 4.8 dmax is pretty impressive. But at $1000 it's getting out of all of these required price ranges.
Nikon 9000 - if you're going to get just 1 scanner and you're not going LF, get this bad boy. This is what I want. I'd prefer to use a flatbed only for LF (I shoot 5x7). But it's $2000.
so there you go. In the aforementioned price ranges, you're looking at the DS IV or Nikon V. Both are good scanners. I'd recommend the V cuz it's got ICE. I always recommend ICE. And, as most people know, I also recommend getting Vuescan.
allan