I can't speak for the Archos, but I am one of the freaks who really think the iPod is a waste of money-- the interface is cute, but IMHO the sound quality is horrible compared to pretty much any MP3 unit I've tried (Iriver, Sony, Creative). You can't use the equalizer or else stuff gets a bit distorted.
So, speaking as a sound geek, I wouldn't get an iPod again (yes, I own a 3G, and I got a major deal for it, and still hate it!
) just because the sound quality isn't there.
The Archos may or may not be better (don't know much about it) but I would go for it.