Many people might not realize this, but #! (either Statler or 9.04) already comes with an alternative window manager, and a damned good one at that...... DWM.
Personally, if I wanted to install multiple WMs for comparison, I wouldn't start with Statler but with a minimal Debian netinstall or GRML (or Arch or Gentoo, if apt isn't a requirement). Reason being I'd want to avoid stuff like GDM (prefer plain startX/xinitrc), network manager (prefer wicd-curses) ...etc.
Tried a few WMs with Debian. Openbox (obviously) with configs imported from my #! install, FluxBox, PekWM, ScrotWM, Musca, Ratpoison, DWM, Xmonad, wmii have all performed admirably. Favourites so far have been ScrotWM and Openbox, mainly for their no-nonsense approach and relatively straightforward configs. Ratpoison is great as well, especially on an old laptop with a malfunctioning touchpad (RP has no mouse support, FYI). I found PekWM and OpenBox to have similar features and performance, though I obviously don't have as much experience with Pek as Hanna does.
I couldn't stand AwesomeWM (it just tries too hard and has shitty syntax, imo... sorry fanboys) and ION3 (probably my fault for not configuring it properly). BlackBox was fun and nostalgic, but seemed a bit plain compared to the other *box WMs.
Compiz standalone is fun if you like bling and effects (way better than Gnome + Compiz, imho), but performance and stability vary depending on version.
Planning to try FVWM and maybe Subtle in the coming weeks, once I find time to sort out a new GRML based install (preferably on my netbook). From what I've heard, FVWM seems the fastest out of the lot with regards to sheer responsiveness.
Among those I've tried, Musca and ScrotWM seem a tad more responsive then the rest, though the difference is negligible, and your mileage may vary depending on underlying packages/libraries/daemons installed.
Cheers.
Edit:
If you're talking about sheer coolness, look at this, http://www.hiprank.com/awesome-vs-dwm-v
monad.html , apply the increasingly relevant "humanity is tasteless" rule, and you'll deduce that DWM is the only cool WM out there (it's the project that gave us the ultra-spectacular Dmenu, after all), by a wide margin .... the rest are just for fakes and poseurs 
Edit Mk 2:
Wouldn't this topic be more suited for the "WM/DE Talk" section?
Last edited by gutterslob (2010-11-09 00:11:46)
Point & Squirt