Xbox 360 games with good replayability

[PiKe]

I'm not prepared to spend £40 on a game that you can basically complete, games like PGR3 and Fight Night Round 3 look ideal games as they're live enabled but what others are there?

 

[PiKe]

Not played the demo so it's not getting purchased.

 

[PiKe]

I haven't played every demo there is on marketplace so far I've played:

Kameo (good but no replayability)
Condemned (see above + slight framerate problems)
NBA Live 2006 (Framerate)
Full Auto (See Above)
Fight Night Round 3 (Pre-Ordered)

Maybe the thread title should have been recommend me some demo's.