I <3 Halo:Reach - amazingly fun and best campaign + amazing Soundtrack
I <3 Halo 3:ODST - best soundtrack + Firefight + Coastal Highway and Mombassa Streets, amazingly unique campaign.
I <3 Halo 3 - best multiplayer levels + Forge + best Custom Games + soundtrack
I <3 Halo 2 - amazing huge fun campaign + soundtrack + Fun multiplayer
I <3 Halo: CE - started it all
The headlong box in the ocean one was creative, and so was another one on High Noon, but the toher were bleh.
Not to mention the fact its kind of pointless because there isn't armorlock in the Anniversary playlist if I remember correctly, nor is there Bro slayer to spawn on your bros co-op style.
EDIT* My bad there is Armorlock.
[Edited on 11.24.2011 12:37 PM PST]