Fallon is more my era. I watched him on SNL for his time there and thought his song parodies were hilarious. He took the torch from Adam Sandler and ran with it. His impersonations and improv aren't bad either, I just don't watch him anymore.
Colbert's show is a bit more grounded in reality. The God sketches always crack me up.
Wisdom is learning from the mistakes of others. Intelligence is learning from your own mistakes. A fool learns neither from the mistakes of others, nor his own mistakes.