^ Dem's da truth! You're absolutely right, Pi, when you say that most Jiggs over-commit to attacking and expose themselves, but to be honest, I've never seen even professional Jiggs refrain from such aggressiveness. It's like they're high on some sort of "predator shark" weed. @_@
One thing I do know is that Samus's utilt and bair outspace ALL of Jiggs options. Utilt especially can kill Jiggs really early. The only problem is the startup time for utilt and sweetspotting/just hitting w/ bair. I know another really big problem for Samus is her lack of priority for things below her, while Jiggs uair is strong (like most of her aerials), has high priority, and kills Samus relatively early. I try to space w/ MCs and nairs but in the end, Jiggs can bair the missiles (and you) and shield your aerials (and all your attacks) really easily w/out having to fear a grab. She can't crouch under Samus's grab, luckily, but that's irrelevant, cuz if we miss...BLAM!
Remember how Samus's heavy weight (low horizontal knockback) combined w/ floatiness (high vertical knockback) makes Falcon's knee>knee>knee easier cuz it doesn't hit upwards at all? Well, the same logic makes Jiggs' wall of pain so much easier to do. Recovering is kind of hit-or-miss. Jiggs can come around and eliminate the bombs while you're bomb jumping but this is only a serious problem on really big stages like DL and KJ64, which won't be legal anymore, come 2012. :'(( I usually don't like playing on those stages against Jiggs since Samus has a hard enough time killing ppl already. On smaller stages, where bomb jumps aren't quite so necessary, it's a guessing game as to whether Samus will recover high or low. That's mostly it. Jiggs can't really kill w/ much other than bair, fair, or uair, so unless she's waiting for you on the stage, Samus plays the evasion game while recovering, avoiding bombing when Jiggs is close, and punishing wrong guesses w/ nair, uair, upB, even dair (although, I don't think that's a good idea). Oh yeah, on certain percents, I think Samus gets a guaranteed dthrow>charged shot on Jiggs, but......that requires a grab. <.< Come to think of it, even if you don't have a charged shot, dthrow=nair=big knockback on a Jiggs.
This is what I've managed to pick up so far from my experiences against the Jiggs players here on the Island that is Long. Hope it helped, maybe a little.
While we're at it, we may as well just talk about Jiggs and Ganon, Jiggs especially. I've never really heard much discussion about him...