Mario Bros is great for practicing catching stuff. New Pork would be ******* fantastic to watch M2K in a 99 minute 3-stock crew battle to see if he's g** enough to try for the timeout. It's actually not that bad a stage given the relative lack of hazards. Mario Bros is great to wreck n00bs, and I think it's a great way to practice catching stuff - also probably makes Fox and Wolf really good. But 75 M is a piece of **** - there's nowhere that's actually very good to fight (those as Pikachu, I love b-throw to death on the right part of the stage). Hanenbow is annoying because the layout allows camping, but it's interesting to play on if someone doesn't just look to outcamp you, and there are enough places to go where camping isn't necessarily the world's biggest issue. Flatzone is small which is why I enjoy upping the stock count way up to watch matches swing in silly fashions.
Long story short: all of them (in my opinion) have at least some utility, except 75 M, although I assume Jigglypuff must love that stage to death.
And Smashville is a great stage. It's not terribly abusable and the platform allows combos without always centering around it (unless you face ICs). Although I'll admit it's not as interesting to play on in free for alls as Big Blue, not even close.
