: Most definitely Battlefield, and I would guess Smashville. Battlefield platforms really help with mix-ups and extending Falcons combos A LOT. Smashville's moving platform can get you some really early kills if the stars align and you happen to get a sweetspotted bair or throw on someone when the platform is close to the blast-zone.
Worst, would be Town & City and Dreamland. While T&C's really low blastzones can be seen as a plus, in addition to platforms, they actually feel like more of a nuisance and work against me. A lot of times platforms on that stage save my opponent and give them an optimal punish, and since they are so high off the ground, i can't really get any sort of combos out of them. And also the platforms moving offstage tend to kill people every now and then.
Dreamland, one word. Wind. Just that one thing, absolutely wrecks me on that stage, as it completely ****s with my recovery, getting rid of any horizontal movement I inputted during the recovery, leaving me helpless and often falling to my death, or open for spike.