Mine isn't really all too funny.
But once I had a picture on my fb called Two-Point
And this guy comments and he's all "I think that deserves more than 2 points, baby"
Or when people ask what I do
"Oh I ride" and they just stare at me blankly.. gotta love it.
Or when I'm talking to my friend about mounting up.. yeah that always gets a lot of laughs.