If you want capacity and do not use it for jogging or other activities that would make a HDD skip, I would go with the Dard Drive players (e.g. The IPOD).

If skipping could be a problem, or you want a cheaper player I would reccommend the Nex II. I bought one for my wife for Xmas and she just loves it. A very simple machine, but I like that it takes regular MP3's no anti copying stuff here. Also it uses Compact Flash. CF offers the largest Solid State card capacities for the least $$. For example I bought her 2 256MB cards for $125. I would look on Ebay for good prices, we paid about $100 without memory.