I wouldn't say I "love" Halo but I like it. It did what it wanted to quite well, that is to say, an epic tale of mankind's sturggle against a race of genocidal maniacs. A lot of people complain that the story is "generic", but I think there are enough twists and turns and notable pieces for me to say "Hey, this is Halo, it differs itself from x game in x way"
Also, the multiplayer in Halo 3 is very fun - just enough different wacky modes out there for me to have a good old time screwin' around online.