Since there's been some debate on this front, I decided to round up every major (and some minor) unreleased exclusive that was at E3 right here. I used IGN and 1up as references, so if there's anything notable I missed, let me know!
*Denotes console only exclusive, title may also be on computer or mobile platforms
**Denotes digital only release, not retail
Xbox 360 (33 exclusives)
PlayStation 3 (35 exclusives)
Wii (50 exclusives)