Out for Delivery - Halo 3
There are few words more touching than these.
Sure, there are some other phrases that are up there, but when waiting for Halo 3 to arrive on your doorstep (and contributing to the biggest day in US entertainment history) "Out for Delivery" is the only thing I wanted to hear.
Now that I've finished the single-player campaign (yes, it's quite short), I'm looking forward to the online multiplayer. With Halo 1 and Halo 2, I played co-op with a buddy of mine in Southern California. The only problem was we had to be in the same location, so it didn't happen more than a couple times...I still remember our plans leading up to the Halo 2 Rendezvous 
Now, with Halo 3, up to four players can play co-op thru the campaign mode (without weekend getaways to shady motels). Add to that the "Forge" option, movies, and the ability to score via the "metagame" and you're looking at one heckuva game.