The first two seasons actually were good with humour. In S1 we had Baltar used for comedic purposes quite a bit. I understand they wanted to take the character in a more serious direction, and indeed I do enjoy the way the character has developed. But they should have him provide some laughs every once and awhile.
I also loved how much of an asshole Doc Cottle was in the first two seasons. Particularly in the second season when Roslin had been deposed. "What I'm about to ask you to do is illeagal and in violation of the oath you swore as an officer." "You're a crappy salesman." Sadly, he hasn't had any good one-liners lately.
Cavil is pretty much consistently funny whenever we see him. "Well this is awkward. He's right, I'm a Cylon. Now, take me to your leader." "Take him to the brig!"