In no particular order:
1. In court, you can't plead stupidity.
2. There is no such thing as a dumb genius.
3. Crazy people laugh a lot. Dumb people get laughed at.
4. Insanity will probably screw up 1-3 parts of your life, stupidity will make all of it miserable.
5. You can be insane and make millions of dollars.
6. Some jobs require insanity.
7. Crazy people make better jokes.
8. Crazy people are more creative.
9. Crazy people are more successful.
10. If you're crazy, you can go to a mental institution. If you're dumb you can go back to kindergarten.

Please, feel free to add to the list.