Daniel Day Lewis is a better actor, obviously...but he's done two movies in the last decade. You're right about Phillip Seymour Hoffman, I'd probably also consider him a better actor. I agree that his accent in Gangs of New York was terrible, and it certainly wasn't his best performance (his South African accent in Blood Diamond was spot-on). I didn't put a whole lot of thought before posting it, but it's not like I'm "struggling" to come up with a better actor. And I definitely don't mean character actors, or indie/foreign film actors. I mean hollywood lead male actors.
I'm wondering which performances of DiCaprio's would be considered downright awful? It would be mind boggling for me to have anyone on the face of the planet watch The Basketball Diaries or What's Eating Gilbert Grape? and try to tell me those are shitty performances. Even his more recent work like in Revolutionary Road, The Aviator, Blood Diamond (even though that movie wasn't that great, his performance stood out) were all good performances.