I recommend an HP. I'm using an HP 2610 All In 1. (I think it's a 2610).
I've tried Lexmark, Canon, and another brand (can't recall it's name), and I've not been satisfied with them until I got the HP from work.
Take note of certain aspects when scanning:
* Do the colours scan correctly (I had green GU pieces scanning BROWN)
* Do Refractors scan ok
* Do graded/encased cards scan ok, sometimes the Scanner only focuses on the first surface, and not the actual card