...since at least Praise Be To Decepticon (in sequence of my personal experiences with them, not release order). This one could be subcategorized as "Best Transformers Trailer Ever." (And yes, it tops that one with Grimlock in it for the same game.)
I don't know why that folky song ("The Humbling River," by Puscifer, and yes I just linked another Transformers music video set to the same song) works so goshdarned well, but it does. It's frikkin' perfect. (One of the top YouTube comments on the video quotes the first line ["Angel, angel, what have I done?"] and replies "JUST MADE THE MOST EPIC [expletive] MUSIC VIDEO EVER!!")
My sister says it works because Transformers has always been, despite its trappings, about a primitive, spiritual people-it's just that they're primitive, spiritual people who have access to awesome technology beyond easy comprehension. I can buy that-Transformers don't so much have nations as they do tribes built around their charismatic chieftains. (I don't think this is a function of trying to rip off the various cultures that have tribes, despite that sort of thing being rather popular these days-it's more to do with the way that little boy logic runs. Younger kids see leadership as having to do with being the toughest and/or coolest. That's why Optimus and Megatron kick so much butt, you know.)
At least part of it, I think, is because it implies a father/son relationship between Optimus and Bumblebee, but doesn't smash one's face with it. Optimus is pretty much every Autobot's dad, so that's a positive.
Also: BRUTICUS IS MY FAVORITE COMBINER.
GRIMLOCK IS HERE TOO.
I think my favorite part of Grimlock in this video isn't his awesome entrance or his awesome transformation or his sheer huge presence, but this simple little exchange of nods that he has with Optimus. Why?
Because I think Grimlock and Optimus work better as two awesome guys who respect each other, instead of distrusting and/or hating each other. Come on, guys, the kind of infighting that we usually see between those two was worn out by X-Men decades ago. I think it's time we move past it.