I think Ryan Gosling is pretty near the top for me. I thought Wes Bentley was going to be a break out star as well, but he hasn't made anything of note in years.
Think Shia Labeouf is getting a tough time here, to be fair. He's just made too much "fluff" in the last couple of years. Something he admits to. AGTRYS proves he can act and Wall Street II may be a move in the right direction but, unfortunately, he's roped in to Transformers 3 and Indiana Jones 5 first so his chance may come and go.
I'd put Kate Winslet in the previous generation...and also don't really rate her as an actress. She can act, sure, but she always LOOKS like she's acting. Like she can smell that Oscar nomination and she's gunning for it.