1. Galaxy
2. SMB3
3. SM64
4. SMW
5. Paper Mario
6. Paper Mario:TTYD
7. NSMBW
8. Super Mario RPG
9. Super Mario Bros
10. Super Mario Sunshine

Galaxy 2 will no doubt break into there.

1. Super Mario Bros. 3
2. Super Mario World
3. Super Mario Bros.
4. Super Mario 64
5. Super Mario Galaxy
6. Super Mario Bros. 2
7. Super Mario World 2
8. New Super Mario Bros.
9. New Super Mario Bros. Wii
10. Super Mario Sunshine

1. Super Mario Bros. 3
2. Super Mario Galaxy
3. Super Mario World 2
4. Super Mario RPG / Super Mario 64
6. Super Mario World
7. Super Paper Mario/Paper Mario
9. Super Mario Bros.
10. New Super Mario Bros. Wii

Note: I haven't played TTYD.

1. Super Mario Bros. 3 (no competition here, biggest release ever)
2. Super Mario RPG
3. New Super Mario Bros. Wii
4. Super Mario Galaxy
5. Super Mario World

To this day, my favorite is still Mario Bros.

Don't know about him but I can give you my view on why I rate SMB3 higher, for those who were the at SMB3's release it was equivalent to what MW2's release is today, no game had ever had such a release and you have to factor that this was an industry recovering from a crash and this was only the beginning. SMB3 showed that platformers can be huge adventures, sure now days people can complete it in 10 or so minutes using the secrets but back then no one even knew of them until a bit later. Going through each world all with a different theme and trait, collecting and managing a good selection of power ups (some of the best in the series, bosses who employ unique tricks, a open ended world map (by 80s standards this was revolutinary for the genre), varied level design, fun rewarding minigames, secrets (i actually found the flute in the castle in W1 by accident funnily enough and never knew some power ups existed until different playthroughs), multi-player as a few reasons.

Now don't get me wrong as a game SMW is better and builds on what SMB3 brought to create an epic but the impact SMB3 had was giant it was not only the biggest a sequel has made over a predecessor but one of the first games that really made people realize just how great games can be, I still remember playing it for months on end, if Galaxy didn't exist SMB3 would be number 1 on my list.

1- super mario world and smb 3 ( cant choose so I could say all stars)

2- super mario deluxe

3- new super mario bros wii

4- paper mario gc

5- super mario galaxy

thats my top 5

Im gonna start play super mario land soon
and the games looks good so it might take a stop in there

Interesting, so it's more of the generational influence and revolution that Bros 3 brought for some people. Kinda like Halo1. Makes sense. I guess I tend compare games with an objective viewpoint. I played both of them around the same time as a little tike, so the natural inclination is to judge both of them as is.  And the random items may appeal to some people.

What really appealed to me was being able to play past levels and find all the hidden routes, levels, yoshi coins, etc. You could actually be a completionist without having to start the game over.

 Thanks for putting that into context and giving some good reasons. To each his own.

I'd say the best 2D Mario is Mario 3.
I'd say the best 3D Mario is Mario Galaxy.
I'd say the best Mario side game is Paper Mario (the 64 version).
I'd say the best game Mario has starred in not related to Mario directly is Super Smash Bros Brawl.

I'd say my favorite Mario game that's not technically a Mario game is NES Open Tournament Golf.

NSMBWii

Multiplayer is so much fun^^