I think Spider-Man's is the best. There's just something about the way that he does it. He sneaks up on ya and basically performs a "boo" on the already twitchy, scared crook. The way that he just scares the bajeezus out of the criminals he chases down...it's just priceless.
And really, any intro that you need the word "bajeezus" to describe it well, just pretty much has to be the best.
Originally posted by Inhuman
JUGGERNAUT!
...Dude. I almost forgot about Juggernaut.
Okay, in terms of bad guys, Juggernaut DEFINITELY has the best entrances. You really just can't beat:
"NOTHING CAN STOP THE JUGGERNAUT!" ::CRASH THROUGH WHATEVER IS IN HIS WAY::
Seriously. It's priceless. I look forward to it in each and every comic he's in.