Daily Show on both counts.
Colbert is great and he's good at satire but he's not that informative. He mentions more news articles but doesn't go in depth with most of them. His interviews are solid though.
His comedy is his strong point and he's ballsy at times but for the most part it's kind of predictable. America = #1 followed by some ironic comment that says otherwise.
TDS just kicks it's [All hail lord Xenu]. Because Jon isn't playing a character no one minds if he gets serious for moments (this comes across more in his interviews) and feels more honest. He's also got a sharp eye for political BS and while he has clear liberal bias he's not that partisan. He also has a solid team behind him which helps out a lot. Then you have his team of Correspondents and while some of them aren't to great at satire they're all fairly funny (John Oliver really needs to go more like Colbert because right now he's not doing himself justice.)
So yeah, my love goes Stewart although Colbert is certainly a solid act. (Have I Got News For You is way better though, at least is used to be...)http://news.bbc.co.uk/2/hi/americas/7582521.stm
(listen to the recording about half way down the page for an expanded version of the article)