My list:
top:
(N)Barack Obama - Instant win :D
bair - Bair's too good ^^
fireball - I'm a camping-type player, so fireball's useful.
(+)uair - Comboable and can even ko/gimp if used correctly.
(-)utilt - I moved this below uair because all it can really do is combo compared to uair.
high:
(+)cape - One of the most feared move in the game, in my opinion, Mario's metagame is based around the cape.
(-)dthrow - Cape is just too versatile, tis why I moved this below cape
(+)dsmash - Can ko if you don't diminish it, FAST, but the way I use it, it's more of a "get out of my face" move.
(-)fsmash - Only reason I put this below dsmash is cause dsmash is too fast :] But fsmash is a reliable kill move.
mid
jab - 2 frames. Enough said :D
(+)nair - Has insane priority that can cut through most of Metaknight's specials. And can even ko.
(-) dair - Good shield pressure move, last move has good priority, what I like to do with this is end this(if the last hit don't knock too far away) with an utilt or grab, Melee style.
usmash - I was about to put this below fludd, but I use this more then fludd, this move can kill :D
fludd - Just like the cape, this is very versatile, but if you miss the initial skeet of the super soaker, you're pretty much a sitting duck...
low
ftilt - This is me being biased, as I'm like the only Mario that <3's the ftilt, I like to end combos with it if I don't want to diminish dsmash, and it's a good "get out of my face" move. Also has IASA frames.
(-)bthrow - I use this to set up edge guarding.. bout it.
(+)fthrow - same as bthrow.
(-)upb - Me being biased again.. I don't really like using his upb outside of recovering, I'd put this below fair and dash attack, but I know it has it's uses.
bottom
(+)dash attack - I probably use dash attack more than most Mario's, I know I shouldn't, but I like the sliding effect :D Can also combo into uptilt at low percent/bair at high percent.
(-)fair - I'd use it more often if some people didn't survive my spikes when they were at high percentages =/ Too slow ><
(-)uthrow - I moved this down, despite someone saying it kills at 180%.. because if you get someone to 180%, pretty much any move can kill them =/
7th layer of hell
dtilt - ugh...
(N)Sarah Palin - Just to make dtilt look good ^^