I say a definite yay to Hirsch. His performance in "Into the Wild" was one of my favorite young-actor performances I've ever seen. It ended up being my favorite film of a top-heavy 2007, mostly due to his realistic and heartfelt performance. I do think he should have at least gotten some Oscar consideration, as in my opinion there's no way that Tommy Lee Jones's "Elah" was as good. He only went up in my book with his ballsy performance in "Milk", where I think he played the most flamboyant and feminine character, and did it incredibly well. He was OK in "The Girl Next Door", I think he was better then most do in "Speed Racer" (which I too find way better and more enjoyable then the general consensus seems to be), and I don't see what was so bad about "Alpha Dog" either. I've yet to see "Lords of Dogtown" but I've heard pretty good things, and "Taking Woodstock" looks great. I like that despite being one of the clear young talents in Hollywood, he's equally likely to take a challenging supporting role when there are obviously bigger but less rewarding ones on the table.
Anyways, I put him way towards the top of my list of best young Hollywood actors, right up there with Levitt, Murphy, Gosling, McAvoy, and occasionally Gyllenhaal/Franco.