There are 2 tier lists now. Be sure to state which one you're using in your RMT threads if you have a non-OU team.
As a note, neither are completely set in stone either. They all change every once in a while.
Smogon's Tier List (click to showhide)
Uber___
-Arceus
-Darkrai
-Deoxys
-Deoxys-A
-Deoxys-D
-Deoxys-S
-Dialga
-Garchomp
-Giratina (Alternate Forme)
-Giratina (Origin Forme)
-Groudon
-Ho-Oh
-Kyogre
-Latias (With Soul Dew)
-Latios
-Lugia
-Manaphy
-Mew
-Mewtwo
-Palkia
-Shaymin (Sky Forme)
-Rayquaza
-Wobbuffet
-Wynaut
Overused (OU)___
-Aerodactyl
-Azelf
-Blissey
-Breloom
-Bronzong
-Celebi
-Cresselia
-Dragonite
-Dusknoir
-Electivire
-Empoleon
-Flygon
-Forretress
-Gengar
-Gliscor
-Gyarados
-Heatran
-Heracross
-Hippowdon
-Infernape
-Jirachi
-Jolteon
-Kingdra
-Latias (Without Soul Dew)
-Lucario
-Machamp
-Magnezone
-Mamoswine
-Metagross
-Ninjask
-Porygon-Z
-Rhyperior
-Salamence
-Scizor
-Skarmory
-Smeargle
-Snorlax
-Starmie
-Suicune
-Swampert
-Tentacruel
-Togekiss
-Tyranitar
-Umbreon
-Vaporeon
-Weavile
-Zapdos
Borderline (BL)___
-Abomasnow
-Froslass
-Gallade
-Roserade
-Staraptor
Underused (UU)___
-Absol
-Alakazam
-Altaria
-Ambipom
-Arcanine
-Azumarill
-Blastoise
-Blaziken
-Chansey
-Charizard
-Claydol
-Clefable
-Donphan
-Drapion
-Dugtrio
-Electrode
-Espeon
-Feraligatr
-Hariyama
-Hitmonlee
-Hitmontop
-Houndoom
-Kabutops
-Lanturn
-Ludicolo
-Magmortar
-Mesprit
-Milotic
-Miltank
-Mismagius
-Moltres
-Nidoking
-Nidoqueen
-Omastar
-Porygon2
-Raikou
-Regirock
-Registeel
-Rotom (Normal Form)
-Sceptile
-Scyther
-Slowbro
-Spiritomb
-Steelix
-Swellow
-Tangrowth
-Torterra
-Toxicroak
-Typhlosion
-Uxie
-Venusaur
-Weezing
-Yanmega
Never Used (NU)___
-Aggron
-Ampharos
-Arbok
-Ariados
-Armaldo
-Articuno
-Banette
-Bastiodon
-Beautifly
-Beedrill
-Bellossom
-Bibarel
-Butterfree
-Cacturne
-Camerupt
-Carnivine
-Castform
-Chatot
-Cherrim
-Chimecho
-Clamperl
-Cloyster
-Corsola
-Cradilly
-Crawdaunt
-Delcatty
-Delibird
-Dewgong
-Ditto
-Dodrio
-Drifblim
-Dunsparce
-Dustox
-Entei
-Exeggutor
-Exploud
-Farfetch'd
-Fearow
-Flareon
-Floatzel
-Furret
-Gardevoir
-Gastrodon
-Girafarig
-Glaceon
-Glalie
-Golduck
-Golem
-Gorebyss
-Granbull
-Grumpig
-Hitmonchan
-Huntail
-Hypno
-Illumise
-Jumpluff
-Jynx
-Kangaskhan
-Kecleon
-Kingler
-Kricketune
-Lapras
-Leafeon
-Ledian
-Lickilicky
-Linoone
-Lopunny
-Lumineon
-Lunatone
-Luvdisc
-Luxray
-Magcargo
-Magneton
-Manectric
-Mantine
-Marowak
-Masquerain
-Mawile
-Medicham
-Meganium
-Mightyena
-Minun
-Mothim
-Mr. Mime
-Muk
-Ninetales
-Noctowl
-Octillery
-Pachirisu
-Parasect
-Pelipper
-Persian
-Phione
-Pidgeot
-Pikachu
-Pinsir
-Plusle
-Politoed
-Poliwrath
-Primeape
-Probopass
-Purugly
-Quagsire
-Qwilfish
-Raichu
-Rampardos
-Rapidash
-Raticate
-Regice
-Regigigas
-Relicanth
-Sableye
-Sandslash
-Seaking
-Seviper
-Sharpedo
-Shedinja
-Shiftry
-Shuckle
-Skuntank
-Slaking
-Slowking
-Solrock
-Spinda
-Stantler
-Sudowoodo
-Sunflora
-Swalot
-Tauros
-Torkoal
-Trapinch
-Tropius
-Unown
-Ursaring
-Venomoth
-Vespiquen
-Victreebel
-Vigoroth
-Vileplume
-Volbeat
-Wailord
-Walrein
-Whiscash
-Wigglytuff
-Wormadam (Grass Forme)
-Wormadam (Ground Forme)
-Wormadam (Steel Forme)
-Xatu
-Zangoose
RL's Tier List (click to showhide)
Uber___
-Arceus
-Darkrai
-Deoxys-A
-Deoxys-D
-Deoxys-E
-Dialga
-Garchomp
-Giratina
-Groudon
-Ho-oh
-Kyogre
-Latias (Soul Dew)
-Latios
-Lugia
-Manaphy
-Mew
-Mewtwo
-Palkia
-Rayquaza
-Shaymin (Sky Form)
-Wobbuffet
Overused (OU)___
-Azelf
-Blissey
-Breloom
-Bronzong
-Celebi
-Cresselia
-Dragonite
-Dugtrio
-Dusknoir
-Electivire
-Flygon
-Forretress
-Gallade
-Gengar
-Gliscor
-Gyarados
-Heatran
-Heracross
-Hippowdon
-Infernape
-Jirachi
-Kingdra
-Latias (Without Soul Dew)
-Lucario
-Machamp
-Magnezone
-Mamoswine
-Milotic
-Metagross
-Porygon-Z
-Rhyperior
-Salamence
-Scizor
-Shaymin (Land Form)
-Skarmory
-Snorlax
-Spiritomb
-Starmie
-Suicune
-Swampert
-Tentacruel
-Togekiss
-Tyranitar
-Vaporeon
-Weavile
-Yanmega
-Zapdos
Borderline (BL)___
-Abomasnow
-Absol
-Aerodactyl
-Alakazam
-Ambipom
-Arcanine
-Articuno
-Azumarill
-Blaziken
-Charizard
-Claydol
-Crobat
-Donphan
-Drapion
-Empoleon
-Entei
-Espeon
-Exeggutor
-Feraligatr
-Floatzel
-Froslass
-Gardevoir
-Hariyama
-Honchkrow
-Houndoom
-Jolteon
-Jumpluff
-Jynx
-Kangaskhan
-Lapras
-Lickilicky
-Ludicolo
-Magmortar
-Marowak
-Medicham
-Mesprit
-Miltank
-Mismagius
-Moltres
-Ninjask
-Pinsir
-Porygon2
-Probopass
-Raichu
-Raikou
-Rampardos
-Regice
-Regigigas
-Regirock
-Registeel
-Relicanth
-Roserade
-Sceptile
-Shedinja
-Slaking
-Slowbro
-Slowking
-Smeargle
-Staraptor
-Steelix
-Swellow
-Tangrowth
-Tauros
-Torterra
-Toxicroak
-Typhlosion
-Umbreon
-Ursaring
-Uxie
-Venusaur
-Weezing
-Wynaut
-Zangoose
Underused (UU)___
-Aggron
-Altaria
-Ampharos
-Armaldo
-Banette
-Bastiodon
-Bellossom
-Bibarel
-Blastoise
-Cacturne
-Camerupt
-Carnivine
-Cherrim
-Clamperl
-Clefable
-Cloyster
-Cradily
-Crawdaunt
-Dewgong
-Drifblim
-Dodrio
-Dunsparce
-Eevee
-Electrode
-Exploud
-Fearow
-Flareon
-Gastrodon
-Glaceon
-Glalie
-Golduck
-Golem
-Gorebyss
-Granbull
-Grumpig
-Hitmonchan
-Hitmonlee
-Hitmontop
-Huntail
-Hypno
-Kabutops
-Kingler
-Lanturn
-Leafeon
-Linoone
-Lopunny
-Lunatone
-Luxray
-Manectric
-Mantine
-Meganium
-Mightyena
-Minun
-Mr. Mime
-Muk
-Nidoking
-Nidoqueen
-Ninetales
-Noctowl
-Octillery
-Omastar
-Persian
-Phione
-Pikachu
-Plusle
-Politoed
-Poliwrath
-Primeape
-Purugly
-Quagsire
-Rapidash
-Rotom
-Sableye
-Sandslash
-Scyther
-Seviper
-Sharpedo
-Shiftry
-Shuckle
-Skuntank
-Solrock
-Stantler
-Sudowoodo
-Torkoal
-Trapinch
-Venomoth
-Vespiquen
-Victreebel
-Vigoroth
-Vileplume
-Wailord
-Walrein
-Wormadam (Ground)
-Xatu
Never Used (NU)___
-Arbok
-Ariados
-Beautifly
-Beedrill
-Butterfree
-Castform
-Chatot
-Chimecho
-Corsola
-Delcatty
-Delibird
-Ditto
-Dustox
-Farfetch'd
-Furrett
-Girafarig
-Illumise
-Kecleon
-Kricketune
-Ledian
-Lumineon
-Luvdisc
-Magcargo
-Masquerian
-Mawile
-Mothim
-Pachirisu
-Parasect
-Pelipper
-Pidgeot
-Qwilfish
-Raticate
-Seaking
-Spinda
-Sunflora
-Swalot
-Tropius
-Unown
-Volbeat
-Whiscash
-Wigglytuff
-Wormadam (Grass)
-Wormadam (Steel)