PCLinuxOS is also nice to use.
However I think the one that really is the bee's knees is PuppyLinux.
It's sheer speed compared with most (if not all) installed ones I've tried is nothing short of phenomenal.
It does just about everything you could want it to do. Top marks to the team there, I'm becoming a convert
Oh just cos the head designer is an ozzie doesn't mean I'm biassed, lolol