I don't believe in tiers because I think that, used properly, every characters taunt is equal. A skilled Ganondorf can use his taunts just as well as Luigi & possibly even better. Plus, with the metagame always changing, the use of taunts changes so there shouldn't be any tier lists. (j/k)
lol
that is win.
yeah, a postitve Yuna post (no offence, but you can really piss people off (like me, lol

))
ok here we go. Squadala!!!
god tier:
toon link down taunt, the only thing that could make that taunt any better is if it caused damage.
lucas: tipping, i love using that for my mindgames
sonic: come on, step it up! how can you people deny the awesomeness that is sonic breakdancing.
luigi: up poses for the win
link: the pose from SSB64
meta: the up taunt
the box
the side kirby dance
show me your boobs!
high tier:
shiek: the one hand-ed handstand
peach: LALALALALALALALALALALALALALALALALALALALALALA!!
diddy: JAZZ HANDS!!
zelda: the wave!!
dk: shake yo money maker Biznich!
the space furries: LANDMASTA!!
mid TIer:
rob: epeliptic sizure!!
ness: the OK!
d3: spin with the belly bop!
mario: the spin
bowser: nom NOM NOM NOM!!
pika: the up one, he is sommoning his POWER! (insert over 9000 joke here)
lucario: the one that's like links
zamus: the one where she throws here blaster
smaus: the one where her blaster arm shapeshifts (kinda)
ike: the one where he throws his sword down and farts
wario: shakes his money maker!
gandw: the bells
yoshi: all are win
ALL TP: they all win.
lower tier: all others except the garbage tier
garbage:
gannon, what the crap!
pit, fail
marth doesn't even taunt!!
for cookies are mah (my) god!!
and for all of you "show me your boobs" perverts look at this!
also, double falcon pawnch!!!