Referenced in The Wedding Singer by Rob. Meant to describe a fine looking woman who has phenomonal attributes, which you would obviously tap. It is a somewhat derogatory term to refer to a woman as a mere piece of meat, which you would easily take all of.
"Hey man did you see that girl Stacy at the frat this weekend?"
"Oh hell yeah, she was Grade A Top Choice Meat."
A person who is not circumcised, or just not cool at all. If you are a no top you are a loser. Anyone you hate can be considered a no top. No tops like to be extremely annoying and tend to be haters. No tops can range from those who have skateboards and say bro, to those who play guitar hero and study Calculus.
bill: Are you gonna give that kid a call back?
bob: No man he's a fucking no top!
another example:
Dave: you gonna eat that cabbage.
Karl: No dude only no tops eat cabbage...you fucking no top!