Moom is great. Having to use a pointing device to manipulate windows is silly. It kind of sucks to pay $5 to get features that really should be part of the OS, but the end result is good.

Shortcuts that I can't live without: Cmd+Shift+Up = Maximize. Cmd+Shift+Left = Move to Left Display (my big monitor). Cmd+Shift+Right = Move to Right Display (my laptop monitor). Cmd+Shift+PgUp/PgDown = Move to top/bottom of screen. Etc, etc.

Divvy is also equally awesome. http://mizage.com/divvy/

I've been usign Moom for about a month now and I can't count the number of times it's saved me from my old gripe with the 'zoom' button.