I think that there are some pretty good limericks out there. Those are the ones that I'll put here. Some are worded so that some people wouldn't dare say them in public (or even want to hear at all). You won't see those here.
A fellow at college named Breeze,
Weighted down by B.A.'s and M.D.'s
Collapsed from the strain;
Said his doctor, "It's plain
You are killing yourself by degrees!"
There was a maiden of Leeds,
Who swallowed six packets of seeds.
In a month, silly lass,
She was covered with grass.
And she couldn't sit down for the weeds.