Well, the thing is that most of the episodes don't have so blatant humor, but there's always something to lighten up. And occasionally there's the "comedy" episode, like Window of Opportunity ("In the middle of my backswing!!") and 1969 ("I'll tell you the truth, Bob. My name is not Kirk. It's Skywalker. Luke Skywalker."). There's also the ending of Bane - I was laughing for fifteen minutes straight after the episode ended.
All in all it's a very well balanced series, and damn fun to watch - I've started to watch all episodes from the beginning two months ago or so, and the quality is remarkably consistent. Story continuity rules too, they often refer to discoveries and people from previous episodes and stuff like that.