I decided to give Awesome a try. Awesome is a tiling window manager like xmonad. I've been using it for about a month, and I like it a lot.
It integrates with GNOME much better than dwm. Most users of dwm don't use GNOME, but I do. Its default settings are a lot nicer than xmonad's. When I use xmonad, I spend all my time futzing with my .xmonad.hs, but I haven't had to tweak Awesome at all the whole time I've used it. For instance, Awesome comes with a ton of layouts built in.
Getting gvim to work perfectly under xmonad required some tweaking, and I couldn't figure out how to get it to work perfectly under dwm. I know that this is gvim's fault because it doesn't follow the exact size prescribed by the window manager, so the bottom part of the screen gets messed up. I'm sure most dwm users don't use gvim--they probably run vim in a terminal. It worked perfectly under Awesome.
Getting NetBeans to work well took even more work, and even now it sometimes freezes in predictable (and avoidable) ways. I had to "sudo apt-get install suckless-tools", and then I added "xterm -e wmname LG3D" to my startup applications (i.e. my GNOME session). Finally, I switched to JDK 1.7.0 and edited /usr/local/netbeans-6.9.1/etc/netbeans.conf so that "netbeans_jdkhome="/usr/local/jdk-1.7.0".
Since Awesome and GNOME each have their own panels, I did some tweaking to make them get along better. I have Awesome's panel on the top, and one GNOME panel on the bottom. I got rid of things from the GNOME panel that were already provided by the Awesome panel. I'm pretty pleased with the result, and I didn't even have to futz with any configuration files to do it.
I really like the keybindings in Awesome. Since I had already played with xmonad and dwm, I didn't really have to re-learn the keybindings for Awesome since they're so similar. I just had to realize that all the keys were based on the command key (i.e. Mod4) instead of the control key.
I especially like having a different set of tags (i.e. virtual desktops) per monitor. That's exactly the paradigm I like the most. I use a big monitor for most things, and I use a lot of different tags. I use my laptop screen just for instant messaging applications, and I only use a single tag.
Plugging in or unplugging my monitor is a pain, especially since I have to tweak the Nvidia settings every time. I know it's a bit "ghetto", but my solution was to restart X every time I want to plug in or unplug my monitor. I think this actually takes less time than shuffling my windows around and futzing with my Nvidia settings.
I have found one Awesome bug. When I first login, my cursor is a clock, and it doesn't go away. If I play with the menus, it does. It's not a big deal, so I don't care.
The default layout is floating, and each tag has its own layout. This default works well for me. I only have to press Command-space to switch to tiling.
One of these days, I might give Qtile a try since it's written in Python and my buddy really likes it. However, in the meantime, I'm pretty happy with Awesome.