Well, doesn't that figure? So that leaves... ODST as last year's most significant 360 exclusive that wasn't an Arcade game? Though that WAS one of the better Halo titles so that isn't so bad.
This is why I'm thinking more and more that you'll be fine getting the PS3 over the 360, the PS3's getting quite a few exclusives worth a damn these days rather than crap like Lair and Haze, and Microsoft seems content to sit back and let the third parties make games, which won't be enough in this generation.
ODST was the best halo game since combat evolved.
But really people, this year should be good for every platform:
360 * Alan Wake
* Crackdown
* Fable 3
* Halo Reach
* Mass Effect 2
* Metro 2033
* Splinter Cell: Conviction
* Risen
* Ninety Nine Nights 2
* Kingdom Under Fire II
* Venetica
PS3 * Gran Turismo 5
* Final Fantasy XIV
* God of War III
* Heavy Rain
* Last Rebellion
* M.A.G. (Beta wasn't great though)
* ModNation Racer
* The Agency
* The Last Guardian
* Yakuza 3
* White Knight Chronicles International Edition
Wii * No More Heroes 2
* Super Mario Galaxy 2
* Arc Rise Fantasia
* Rumoured New Zelda
* Tales of Graces
* Metroid Other M
* Monster Hunter Tri
* Sin and Punishment 2
* Red Steel 2
* The Grinder
* Gladiator A.D
* Trauma Team
DS * Ace Attorney Investigations: Miles Edgeworth
* Again: Eye of Providence
* The Another World
* Dragon Quest VI
* Dementium 2
* Dragon Quest IX
* Final Fantasy Gaiden: Four Warriors of Light
* Ghostwire: Link to the Paranormal
* Ghost Trick
* Golden Sun DS
* Infinite Space
* Last Window: Midnight Promise
* Okami Chronicles: Tiny Sun
* Pokemon HeartGold/Soul Silver
* Project Monster
* Shantae: Risky's Revenge
* Shin Megami Tensei: Strange Journey
* WarioWare: D.I.Y.
PSP * Metal gear solid: Peace Walker
(Thats all I can think of off the top of my head)
And we haven't even seen what is yet to be announced at E3 :)