Help me buy an mp3 player

So, as you’ve probably gathered from the title, I’m thinking about buying an mp3 player. However, I thought I’d consult the collective mind of the SDMB beforehand. Is one brand preferable to others, or should I just go for the cheapest price? How much capacity is enough? I’ve noticed some as low as 512MB, which seems rather low for a device that is to contain many sound files. Is there anything I should look out for? Thanks in advance for all your help.

Here are a few recent threads:

http://boards.straightdope.com/sdmb/showthread.php?t=378838&highlight=player
http://boards.straightdope.com/sdmb/showthread.php?t=378458&highlight=player
http://boards.straightdope.com/sdmb/showthread.php?t=369669&highlight=player