Such a list depends highly on the usage of your computer and your experience I use i3 [1] (tiling WM), and never looked back - I can't force myself to use another DM/WM. But it's not for everyone.
The wonderful thing about linux is choice - I can use something completely different than another person - tweaked just the way I like it. Why I chose a tiling WM? I work a LOT on the commandline (only exception is the webbrowser - everything else runs on my CLI). So I don't use my mouse very often - a "classic" interface would be wrong for me - I'm used to harness the power of keystrokes ;-) A window always fills the screen, a new one will automatically adjust, so both are open on the screen without overlapping - it's kind of difficult to explain. There are some geeky screenshots and videos on the i3wm homepage. So - for everyone interested, try a tiling WM - there is a learning curve (depending on different aspects, it might be quite high) bit in my case it was worth it. I would not recommend it for beginners, the look and feel is extremely different.
Tiling window managers are awesome! I never was able to find one that played nicely with a pretty GUI environment, with Gnome 2 + Xmonad being the sole exception. And Gnome 2 feels a bit outdated these days. What I really want is a tiling WM + something like the Unity Dash where you get automatic Super+1, Super+2, etc. keyboard shortcuts, corresponding to the position of icons on the dash. Basically something with graphical cues that go along with the keyboard shortcuts. But I could never quite make it work.