I install every game (except Halo 3, the developers stated it does NOT run better from the HDD because of programming issues.) that I actively play.

Why?
Less noise.
Faster loading (Even games like Tekken where It's cut 5 seconds loading between characters chosen/the fight. That saves me a good minute or two here and there which really adds up.)
Possible less heat output (I heard using the game on hard drive as oppose to constant disc spinning helps prevent RROD but I have no proof of this.)
Less scratchs on disc (Once installed the disc will only be checked once on start up, so the disc will have less wear and tear.)

uh depends does 30 seconds eqaul long load to you cause i don't really have a problem with load times.

Can you guys explain how you set up your Xboxes to record TV?  A couple of you said something about Windows Media Center.  Is there a link or something you could provide that would tell me how to use my Xbox as a Tivo?  How much control do you have over the TV schedule?  Probably not very much if I can imagine.

Playstation would probably be the much better system as a recorder since Sony actually allows to upgrade our hardrives to more meaningful sizes.

The problem with that though is that people would just rent and install games and then never actually BUY any games.

@OP: It doesn't make a difference selecting play from the hard drive or just clicking on the game to start. You can tell the game is playing from the hard drive because the dvd will only be checked at the start-up of the game and it won't be accessed while you play. Installing makes a big difference on some games like Fable 2 and Lost Odyssey, but on others it is minimal. It's still nice playing without the drive spinning all the time and quieter.

Thanks everyone! *starts intalling every game except for Halo 3*

Obviously. But it'd still be nice.