I've noticed a bit that Joe and Brian do in some episodes, and I find it hilarious...
It's the bit where Brian will say something of a sexually disgusting nature, and it completely grosses out Joe.
The most recent example of this was in the "Mathers Of The Heart" episode:
Helen is telling Joe and Brian about her date with Lowell, and says that when they were saying "Good-night", Lowell kissed her hand.
Then Brian asks, "Where was your hand?" and Joe makes this disgusted face and starts yelling things like "Aw, TIME OUT! CHECK PLEASE!" and things like that.
I just find Joe's disgusted reactions to Brian's comments SO FUNNY....the only problem is that sometimes Joe's "grossed out" comments almost get drowned out over the studio audience's loud laughter!