See, Gears 3 was my favorite for a lot of reasons. I love Cole. I love everything about that character. He's basically the poster child for what you describe as the meaning of Gears of War. But I also love his greater backstory that was flourished throughout those opening levels, and to an extent, the books that were released between Gears 2 and 3. Say what you will about Karen Traviss's works everywhere else; she can write Gears.
Cole is man that came from so much loss and tragedy, and puts on a show for everyone else to feel a little better about the crap world they've been dealt.
Another reason 3 is my favorite was the Tower Defense-esque spin they did for the 2nd iteration of Horde Mode. I've had so much fun in that mode in the years since release.
3 is also pretty much the ultimate couch shooter. I remember nights where a bunch of us would play the story mode on arcade rules just for the hell of it (with all the crazy modifiers like big head mode, chicken, etc.)
I had reservations about 4 being made as I expressed last year during the E3 thread, but seeing how this threat isn't the Locust reborn, I'm willing to give Coalition the benefit of the doubt on their first game. The beta is this weekend. I'll be playing it. I'll let you guys know.
I hope I can play as Bernie again. Loved her in the books.: