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I have a canon scanner. It's pretty good. I've used Epson scanners, too. They're much faster, and the quality is really nice, too.
 
I have an Epson Perfection 2450 photo and I love it. It's really fast and I get really good results. The biggest pitfall to the whole thing is that you can't remove the glass to clean dust off of the underside, but the dust isn't anything that Photoshop can't fix. I tried an older Canon once and it took FOREVER to scan (this was in the pre-OS X days)---the driver was very invasive to my system and I had a heck of a time removing it...I'm sure they've come a long way since then (I hope).
 
Epson all the way. 2450 rocks. but even if you dont get yours that high, its still pretty good. They use the 1660 at photo labs - I would know, I work at one.
 
I had a CanonScan Lide last year and I took it back because it was slow and the colors were never correct. Also it did terrible scanning photographs. I replaced it with an Epson Perfection 1250. It rocked. It was everything the Canon was not. Colors were great. It had excelent contrast and reproduced photographs near perfectly. The only problem is it was USB and I am an impatient person. So I took it back.

I would say definitely Epson over Canon. Which is saying a lot since I don't like Epson as a company but they have a good product.
 
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