Since I work at Gamestop, sadly enough, I decided I'd post our list of pre-order bonuses, just as an FYI I guess.

Army of Two: The 40th Day: Early access to the new "Extraction" multi-player mode.
Assassin's Creed 2: In-game map of the Palazzo Medici.
Battlefield: Bad Company 2: Instant access to the AKS-47.
Bayonetta: Collection of 8 poses in tear-off posters & $5 off total cost.
Blur: Double rewards for first 10 multiplayer races; -Ord Bronco unlocked; survival mode (?)
Drawn to Life: Next Chapter: Five bonus hero templates.
God of War III: GoW III demo and Phantom of Chaos Kratos skin.
Gran Turismo: 2009 Bugatti Veyron 16.4 unlock.
Guitar Hero: Van Halen: Van Halen T-Shirt.
Harvest Moon: Sunshine Islands: Plush pig. Animal Paradise: Plush duck.
Left for Dead 2: In game bat and $5 off total cost.
MAG: Beta access & in-game character.
Mass Effect 2: Terminus Armor (+10% speed, +15% shields, reserve ammo+1) and M-490
Blackstorm gun (fires a singularity projectile that draws in nearby enemies, then hurls
them away).
MX vs ATV: Reflex: Five exclusive race events.
Naruto Shippuden: Clash of the Ninja Revolution 3: Sasori's thumb ring.
Red Steel 2: In-game sword.
Resident Evil Darkside Chronicles: Darkside Chronicles T-Shirt.
Rogue Warrior: $10 off total cost.
Silent Hill: Shattered Memories: Soundtrack.
Splinter Cell: Conviction: In-game semi-automatic shotgun.
Star Trek Online: Codefor USS Enterprize.
Tony Hawk: Ride: Access to Quicksilver level.

Again, not too much, just some interesting things. Also, not everything might be available, because we often suck at keeping these in (A.K.A. Employees take them). I can't say I've Pre-ordered a game just for the bonus, but its something to think about.