If you really want a good photo scanner, you better be willing to do without the autofeeder option. Scanners with autofeeders are generally designed to be better for text (OCR). Next, decide if you'll want to scan slides/negatives/other transparencies or just prints. If you do need to scan transparencies, then you'll want a scanner with a transparency unit [TPU] (built-in or optional)...most TPUs are for 35mm, but some are around 4x5in or full size. Then, decide on a price. Some recommendations:
Epson 2450 Photo ($400) - 4x9in TPU 2400x4800dpi Firewire/USB 2.0
Epson 2400 ($230) - 35mm TPU 2400x4800dpi USB2.0
Epson 1640SU ($450) - 1600x3200dpi AUTODOCUMENT FEEDER USB/SCSI
UMAX AlphaVista ($400 pcmall.com) 1200x2400dpi (SCSI only!) Full sized TPU
UMAX PowerLook III ($500 w/o TPU; $700 w/ full size TPU). 1200x2400dpi very good
If you want the real deal, be prepared to spend $4000-$20,000 for a decent flatbed. But since you're asking, you probably don't want those anyway. Then there's the whole host of cheapies for under $200.