Both were great and were perfect for the movies they appeared in.
But I'd I have to pick Heath Ledger. When it was announced he was playing the Joker people lost their shit saying he couldn't do it. Then when the first poster came out and people were like holy shit. He was something we'd never seen before.
Please don't think I'm knocking Phoenix's performance. Perfect for that movie he was in.
It kinda sucks The Dark Knight came out that year cause Robert Downey Jr absolutely killed it topic thunder and would've won the Oscar any other year.
My question is, would Ledger have won the Oscar had he not died?