Mario is quite a guy. He's perfectly willing to go to great lengths, however insane they may be to rescue a princess that rewards him with nothing but a kiss or some cake. Mario's jumping skills are unrivaled (OK, that's untrue, Luigi has the superior jump game) but he's never been able to save the day without some kind of assistance. Fortunately, Mario and company have some of the most useful, diverse power-ups in gaming and I present to you, my favorite of the lot.
Fire Flower / Fire Mario
Before Tanooki Suits, Hammer Suits and Cape Feathers, this was the original OP Super Mario power-up. Mario gains the ability to chuck balls of fire at his enemies and for the most part, this hand tossed heat is super effective. The fire balls bounce on the ground and don't disappear until hitting an enemy or a solid object, so this baby gave Mario long range combat abilities on top of a pallet change. If Lakitu is around, having this power is a huge plus since the Spinys he likes to rain down on you cannot be stomped out. As good as the Fire Flower isn't even it has limitations. It can't do anything against foes with super hard shells and enhanced durability but the majority of Bowser's minions can't stand the heat and this also applies to the Koopa King himself in most games.
Whenever you hit a ? Block and a Super Star comes out, you know good times are ahead. While the powers the Super Star give you are temporary, they usually last long enough for you to wreck a good chunk of the baddies in your way. The Super Star is a god mode of sorts for Mario. While in use, enemies can't touch him. Really, they can't touch him because if they do, they are granted the sweet release of death as Mario changes colors again and again. Taste the rainbow, indeed. The Super Star is so dang awesome that it has its very own them for you to jam out to while mowing down Bowser's army.
Super Leaf / Raccoon Mario
Super Mario Bros. 3 introduced a slew of new power-ups, chief among them was the Super Leaf, which, in addition to giving our hero a sweet set of ears and a tail, granted him the power of flight. By running to build the P meter and using the Raccoon Tail, Mario can soar to new heights. The tail could also be used to slower Mario's decent during falls and this really came in handy during the game's numerous sections of precision platforming. The next power-up was a superior version of this one and I love it a lot, but there's just something about seeing Mario and Luigi with ears and tails that isn't a full blown suit.
Tanooki Suit / Tanooki Mario
All the powers of the Super Leaf with the super awesome bonus of being able to turn into a statue, where you can stomp out most unkillable enemies or buy you some time to bypass them. Mario also looks cute as a button. In Super Mario Bros. 3, the Tanooki Suit wasn't near as common as the Super Leaf, so I would try to hold on to as many as them as I could. In Super Mario 3D Land, where it made a long overdue return, the Tanooki Suit was everywhere but lacking the power of flight.
Hammer Suit / Hammer Mario
If you want to attain godhood in Super Mario Bros. 3, look no further than the Hammer Suit. For the unaware, you may be thinking, "It lets you throw hammers, right? What's so great about that?" You get to throw hammers, yes, but those hammers are so freaking powerful that they wreck everything in the game. Thwomps? Dead. Boos? Deader than dead. Even Bowser's hide can't stand up to those mighty hammers! It isn't just super strong offense that the Hammer Suit grants you. The Shell is fire proof and since you see a lot of Piranha Plants that shoot fire late in the game, that helps a lot. You lose the ability to slide down slopes while wearing a Hammer Suit and its an extremely rare power, so losing it is one of the worst feelings in the world. The Hammer Suit is one of the most broken power-ups in Super Mario history, ranking right up there with my next entry.
Cape Feather / Cape Mario
Super Mario World didn't offer much in the way of new power-ups. But the sole new item it did bring (not including Yoshi) is widely considered one of if not the greatest power-up in Mario's extensive catalog. The Cape Feather is allows Mario to perform a wide range of maneuvers. You can us it to spin to defeat nearby foes and protect Mario from most projectiles. You can use it to slow Mario's plummet. It has flight capabilities and in the hands of a skilled player, the gliding can be used to keep Mario air born for the duration of an entire horizontal level and there in lies the Cape Feather's brokenness. No wonder the Cape Feather didn't make a comeback until Super Mario Maker.
Carrot / Bunny Mario
Mario's jump in Super Mario Land 2 already felt float but for even more hang time, you've got to try out Bunny Mario. Touch a Carrot and Mario sprouts bunny ears and while they don't let him fly, they do allow for the best slow descent of any Super Mario power up. One could argue that the Carrot makes Super Mario Land 2 even easier than what it already is. That certainly doesn't make it any less of a cool item to have.
Metal Cap / Metal Mario
Super Mario 64's power ups don't function the way they did in previous Super Mario games. Rather than being extensions of Mario's abilities, the power ups in Mario's first 3D outing are situational and while that may be bummer for some, they are fun to play with when the game gives you the chance to do so. The Metal Cap turns Mario into a shinny, heavier version of himself that's impervious to harm. With Mario's extra weight, he can sink to the bottom of the ocean and reach places that swimming wouldn't allow. Like the Super Star, the Metal Cap is a temporary power up. With each step Mario takes, clanging can be heard as can a killer remix of the Super Star theme.
Mega Mushroom / Mega Mario
Talk about being on a power trip! If the Super Mushroom turns Mario into Super Mario, the Mega Mushroom turns him into Mega Mario, a tower figure capable of dishing out wanton destruction on Goombas, Koopas, bricks, pipes and pretty much anything that isn't the ground. There's nothing quite like barreling through everything in your path. First introduced in Super Mario 64 DS and later used in New Super Mario Bros., the power-up made a much needed return in Super Mario 3D World where four players could wreck havoc on Bowser's mooks that have invaded Sprixie Kingdom.
Propeller Mushroom / Propeller Mario
One of the new power-ups added to New Super Mario Bros. Wii, the series first four player game, the Propeller Mushroom decks Mario and company out in what looks to be sweat suits with cute helmets that allow them to take to the air and come back down slowly. It isn't exactly flight based like the Super Leaf or Cape feather, rather you shoot straight up into the air. You do of course still have control of where you land upon coming down. This really comes in handy for those levels with plenty of bottomless pits or for those not too confident in the platforming skills. As shown in the image above, a player that lacks the Propeller Mushroom can hitch a ride from someone who does.
Cloud Mushroom / Cloud Mario
It looks like Mario's wearing a ton of marshmallows on his head, but that's just the hat change Mario gets when using the Cloud Mushroom. Appearing in Super Mario Galaxy 2, a game where most power ups are situational, Cloud Mario adds to something the plumber was already insanely good at: jumping. Cloud Mario can create up to four cloud platforms before another Cloud Mushroom needs to be found to continue using it. The neat thing about Cloud Mario is that it can be used with all of Mario's jumps, meaning you can get more mileage out of it with long jumps.
Super Bell / Cat Mario
Mario's been a raccoon dog, a frog, a penguin, and a flying squirrel. With all the other critters Nintendo could have gone with, a cat was the last thing I was expecting. But when I saw Mario and the gang running around in their cute little cat suits, I knew it was clearly meant to be. The Super Bell allows Mario, Luigi, Peach, Toad and Rosalina (spoilers, she's playable) to walk on all fours run even faster than than normal, climb walls or trees and do this cool downward strike that tends to get most players killed. This power up is so cool that even Bowser gets in on the action at the climax of Super Mario 3D World.