A while ago I was grinding through the ranks of bots on an app and would only go to the next level when I could smash the current bot opening with bongcloud.
Someone from my local chess club has an account on Lichess where he only uses Bongcloud-like openings. He has reached a rating of over 2000 and crushed some 2200's (that's almost professional level for those who aren't familiar with ratings).
Coca-Cola gambit for the slightly more advanced (even though I have invented a brilliant countergambit against it). For black the fried fox defense is pretty OP too.