Gnome seems to me quite slick with some nice default features.
Gnome2 is even an improvement on that- faster, more stable (it seems) and less fiddly. And with Anti-Aliased fonts as default (might depend on distro). Gotta love it!
Of course for speed you might want to try a window manager only- i.e. blackbox/fluxbox, windowmaker etc. Blackbox being my current favourite on my laptop!