I don't really have a favorite quote, but here's some I've found --
There are only two things that are infinite - the universe and human stupidity. And I'm not so sure about the universe. -Albert Einstein
Everybody is a genius. But if you judge a fish by it's ability to climb a tree, it will spend it's whole life believing that it is stupid. -Albert Einstein
The difference between stupidity and genius is that genius has it's limits. -Albert Einstein
A classic is something that everybody wants to have read and nobody wants to read.
Three may keep a secret, if two of them are dead.
Fish and visitors stink in three days.
And here is one more -yes, not as funny-