Gosling was good in the notebook but seriously? Haha, I thought he was REALLY good in Half Nelson/Lars and the Real Girl, Drive was good too and The Ides Of March, wow haha.
But that's not to say Joseph Gordon-Levitt is a bad actor, in fact, he is also one of the best of their generation. They both deserve Oscars.
Joseph's performance in 50/50 was very convincing, and it became one of my favourite movies in the recent years (the others being Drive and Moneyball) and I loved him in 500 days of summer! They also both had really non-mainstream films that were good, namely Mysterious Skin(Joseph Gordon-Levitt) and The Believer (Ryan Gosling). Comparing them is like comparing bacon and cheese (wtf?) They're both just really good and I wouldn't mind them in a film together in a movie!