He has been snubbed a couple times by the Emmy being given to John Oliver, he mentions it often, in my mind Colbert has the best writing team, and Colbert himself is at almost superhuman level when he improvises, which is fairly often. John Oliver doesn't even come close, all he does is find one valid topic and then yell for a half hour.
Fallon is more middle of the road for old people, but does some good music impressions sometimes.