I've run the gamut, from GNOME, to Xfce4, to LXDE, etc...
They all have too much extraneous software.
I'd much rather build a system up, rather than tear it down, in my quest to squeeze as much performance out of my netbook as I can.
Ditto. For me, however, the performance benefits of going fairly minimal are kinda secondary to the productivity benefits of choosing tools that stay the hell out of my way.
While there's a lot to like about dwm (I rather like its tag concept as a replacement for workspaces, for instance), I find it a bit limiting for my purposes. Spectrwm is another good one, and it gets too little attention. Xmonad is pretty good. For floating rather than tiling window managers, I think AHWM is pretty awesome, though it has been abandoned for years; it could stand to be picked up by a new maintainer.
I ended up with i3, though; it's tiling with decent functionality, including its native support for tabbing windows. It used to be better, actually, in that it was easier to mix and match different window arrangement styles within a single workspace, but even after making that marginally less usable it still does more in that regard than other WMs I've tried out.
For me it's not about resource consumption, but rather, the plain suck factor (of Gnome 3)