I didn't actually hear about it from E3, but I heard about Legendary: The Box in a report after E3 had concluded. I can't say I know much about it, but I have always been a fan of Greek/Roman mythology. If you get to fight against multiple creatures from the past, you can almost always count me in. I can only hope it doesn't become another generic shooter with pretty graphics and monsters.
If not that game, Turok was another nice surprise. I was a fan back in the N64 days, and the gameplay looked pretty solid. I'm excited.
And of course, no "most wanted" list would be complete without Assassin's Creed. That game has had my attention for a while now, and I am extremely optimistic about it turning out nicely.
There are more that I am anxiously awaiting, but these grabbed my attention the most.