I get really aggressive with Diddy, Shiek, Yoshi, Mr. G&W, Fox, Pac-Man, and Falcon. I just want to string combos all day with those characters. Jigglypuff, too. I think the most aggressive I get is when I play as either Fox or Diddy. Pac can also be fairly aggressive, even though he's more of a wait and see character, especially with his very punishable grab and hydrant. Once you get them in your preferred area, though, you can really bring the pain with Pac's aggressive pressure. His dash attack can be easily read, so just be sure when you're being aggressive with him to try and not spam it. Okay, maybe Pac can't be too aggressive, but still, I notice when I get a string of attacks going with him, 0-death is very possible. Especially with the correct fruit stored and knowledge of when to use his side-b, which is so satisfying to kill with.