U2 just gave a famous NYC pizza place an endorsement that's worth a million bucks.

Bono, The Edge and Adam Clayton hit up Famous Ray's Pizza Wednesday night as our photog watched them salivate over the pies on display.  

The band drew a crowd outside as fans tried snapping away. It got so crowded, cops led an escort ... for Bono, as he left with pizza box in hand.

So, what d'ya think? Does Bono fess up to our photog on the type of pizza that drew him in?