That old scanner was probably SCSI, though most of the ones that shipped with a card used a crappy SCSI card you couldn't use for anything else. Most of the high-end scanners are both USB and Firewire; the cheaper ones are USB only. Firewire is faster, but it won't make much difference except with the larger scans.This site
has some decent scanner reviews, though I haven't looked around there in a while.
Aphasia covered most of the high points. If you're scanning slides (and you don't want to pay for a dedicated slide/film scanner) you might want to look for a scanner that can a lot at once (some offer just a strip adapter that allows you to scan four at a time, while others offer a grid that can do 12 or 16 at a time, and software that will automatically separate the individual slides out of the scan). Some scanners offer a lid (and sometimes depth-of-field adjustment) that allows you to scan 3D objects
It would help if you were more specific about what you're looking for and the kind of scanning you're planning to do.