[tomkarlo]

Get the app "Cinch" from the app store if you're on OSX, and especially if you're on a big monitor. It's frankly better than a maximize button, as it also lets you do side-by-side half screen windows.

(I am not associated with this app, just a happy customer.)

[brandonbica]

Personally I like SizeUp better. Keyboard controls for multiple positions and layout combos, moves windows across spaces and monitors too. It even has border control. One of the first, most useful apps I found when I made the switch to my imac.

Both can be gotten through Irradiated Software (http://irradiatedsoftware.com/). Free demo.

I'm just a happy customer too.

[lazerwalker]

I personally use BetterTouchTool (http://www.boastr.de/). It has basically the same functionality as Cinch and then some (maximize, auto-resize to split views, move windows across spaces/monitors), but it's (a) free and (b) also lets you define custom touch gestures to activate them (and any other actions you want) with a MacBook trackpad / Magic Mouse / Magic Trackpad.