Awesome is great, using it for quite some time now.
Otherwise I would suggest I3 and as vezzy says , DWM , the mother of all tilers
When it comes to speed it really doesnt differ much , DWM is pure C so in theory the fastest it is however very minimal.
After using it for some time I really wanted some more fancy and modern features, so I switched to awesome.
Awesome has some stuff built in that is kinda neat, only thing I dont like is LUA , weird syntax language.
You must really like editing config files though..
Best of all is that you dont need that stupid mouse anymore, all custom keybindings for me.
Pretty much noone else has a damn clue how to control my box