Yoshi's Island. But that's for another topic (or if this one gets mind-numbingly dull).

Anyway, a disclaimer: this is absurdly close. The two of them are my second and third favorite games ever, so I'm not suggesting one of them is bad, or even less than superb for that matter.

Super Mario Bros. 3. First off, it has variety in its favor. World's tropical theme is refreshing, but it also limits it. The airships are a nice change of pace.

Then I feel 3 has a cooler rogues' gallery than World. Actual Hammer Bros (and boomerang, fire, and sledge), Para-Beetles, Chain Chomps and Fire Chomps, Buster Beetles, Hotheads, the varieties of Pirahna Plants...it takes the lead there.

Next we get to power-ups. Now, between the Cape and Yoshi, World puts in a very strong showing. But that's only two, and both of them render the third and last major power-up, the Fire Flower, rather useless. So many enemies in World are fireproof, or just plain easier to kill with the cape. It also no longer has the monopoly on underwater combat.

Bros. 3 not only has a lot more power-ups, but balances them nicely. The Fire Flower's only real competition is the Hammer Bros Suit, and you can choose power or range/accuracy. Sure, the Tanooki renders the Raccoon Leaf obsolete, but it's a lot more rare. And then there's....Kuribo's Shoe.

Finally, 3 has a cooler final world than...World. Tanks and battleships trump a clown copter. And it has possibly the best Bowser battle ever.

Again, Mario World is still better than 99% of video games.

My pick is Super Mario World.

Although, I do agree with you that 3's enemies are cooler, and of course that they have more powerups. World's cape is the best flying powerup ever though, in any Mario game.

World is a bit more approachable, and is perhaps easier to master than 3. I like to speed run World sometimes.

The koopas are cooler in World for many reasons; including weird AI, various colors, and the many ways one can do damage to other enemies with the koopa shells (throwing in the 'up' direction, better hit detection when spinning the shells with the cape {unlike the racoon tails}), and most of all, Yoshi's many uses with them.

And Yoshi himself is what shines the most about World. I was never a big Yoshi fan overall, but how you got to use him in this game just made the aspect of platforming so much more fun than without him.

But I concede that Kuribo's Shoe owns everything and anything in existance. If only World had that shoe!

I also agree that both World and 3 are tremendous games. In fact, 3 is likely the third best game on the NES for me (Zelda 1 and Super Mario Bros trump it).

World, on the other hand, is likely my favorite game of all time. I have probably played it more than any other as well (except World of Warcraft and Super Smash Bros. Melee, but I am burned out on both those games forever, whereas I am not close to burned out on Super Mario World).

I hope the typos are few in number, I am doing this kinda late.

Fair enough. And since only two of us seems to think this is an "Eternal Question", I'm gonna go off-topic and ask you to come on IM.

First off, I am saying that these are simply the best two Mario games ever to hit the 2-D scene, and are 1 and 3 over with me with Super Mario 64 as the best 3 Mario games ever.

Super Mario Bros. 3- This game had it all. The start of the Koopalings. The enemies were also vast and different. From the classic goombas and koopas to the upgrade of Lakuta and the Hammer Bros. I also like the fact that the final level of the world was an air ship.

The items make this game better than World. First off, you have the Raccoon suit, the Frog suit, and even the Hammer Bros. suit. Why they took these upgrades away I'll never know. There was one upgrade you only got once in Sky Land. It was Kuribo's Shoe and you rode in a shoe. That was cool level.

Bowser- Simply the coolest fight on the 2-D scene. When I first saw him, I was amazed at how much he changed from the original game.

Overall, there is a reason why this in the number one selling game of all time. It was simple for most people, and still had the replay value for those who wanted to keep coming back to it. Plus why I choose it, was because of the shock factor of enemies that we already saw and the introduction of some even cooler ones.