Just to add to the comment above, the Rockchip players will handle XviD format movies once they have been converted to the correct screen size, using something like AviConverter or Xilixoft's DVDtoMP4 converter (I know I keep going on about the latter, but it works fantastically !!).
How to do this, was covered here:
It all depends on your budget. For around £30 / $60, you'll get a 2.4" Rockchip player on Ebay / Uxcell / MP4nation which will have 1~2GB on board, with the option to slide in a 2GB MiniSD card.
For £60 / $120, you'll get a handsome Meizu M6, which many of the Rockchip units try (fairly well) to imitate. The screen is much better with the Meizu.
My opinion only - don't waste $40 on a AMV player - if you are buying within a low-ish budget, chuck another tenner in and get a Rockchip player.
The AMV players are 'old' technology now - yes, we marveled at them 2~3 yrs ago, but things have moved on!! If you DO decide to get a AMV format player, be VERY careful not to get conned into buying a 4GB~8GB player for a 'what-seems-to-be-a-bargain' price. They are often 'hacked' by unscrupulous Ebay sellers who are looking to shift their old tat
. Look for feedback within Ebay, and tags like 'Genuine 2GB' are possibly more comforting.