I actually enjoyed playing Lego Star Wars co-op.  I got the game as a gift and was a little skeptical, but once we started playing, it was a blast!  The great thing about this game is that it does take alot of time to complete ... you will not be able to finish the game in a few sittings only.

I'm dissapointed there are not many games offering split-screen co-op gameplay.  I was especially disapointed with COD3.  GOW is alot of of fun split screen ... but sadly it seems there is not much support for this mode, except maybe for arcade titles.