@H:
Okay, then I'll list them because I'm bored.
Buggy - That one guy he blasted with the cannon
Kuro - His own crew
Kreig - Once again, his own crew, plus some chefs
Arlong - Pretty obvious
Mr. 3 - Dorry and Broggy
Wapol - Can't think of any. Dalton maybe?
Crocodile - Those 4 guys
Bellamy - Roshio the Executioner
Ener - Kamakiri
Foxy - Not sure
Lucci - Also not sure, him taking out Luffy in the first round at Galley-La headquarters?
So basically, all those guys were jobbers, and I have a lot of time on my hands.
Not exactly what I saw, but that's okay I guess.
I have H.W. ^^ Time to list!
Buggy - Yeah, the one with the bomb, but also those guys he used as a shield against Luffy's Balloon.
Kuro - Yeah.
Krieg - He had that one guy who complained about Mihawk and then was shot..
Arlong - Yeah.
Mr. 03 - No boss, and actually Dorry was only for plot, so you can't really count him.
Wapol - Basically he didn't need any, since it was already fairly obvious plus appearantly EVERYONE were pissed at him. 
Bellamy - Read Mr. 03, only replace with Cricket.
Enel - He had alot around him to get pretty evil already, kinda like Wapol. He did crash the God's level on that bean stalk, so maybe that fits.
Foxy - No need to. That arc was cheerful, so why put him to evil?
Lucci - No boss. The actual boss was the Buster Call, remember? Lucci was just the strongest, which always happened so far to be the boss. The BC though, crashed a whole ship with thousands of soldiers just to get Luffy, which has obviously kept with "The" Lucci for some time now. I know it was partly because of an admiral, but in the name of the BC as he was part of it.
It's not only limited to shonen only, too. Almost any series should have this kind of scene for the boss if he is really evil. It gets the hero snapped, plus it shows us how evil he is. w00t.
Whew. H.W time.