Hello. Here is my tier list, broken down by roles. Certain champions in a favorable lane matchup are better than they are depicted on this list. For example, J4 top would be heavily favorited against a higher tier character if he has a better matchup than they do.

When I write my tier lists, champions in a tier I consider of equal power, unlike elementz's. So, a champion who is #1 in tier 3 is not necessarily stronger than the last person in tier 3. That's just how I choose to do things. If your champion is not mentioned, it probably means they suck so hard I forgot to include them. If I DO forget a champion, please mention it and I will add them. If I don't mention a champion for a role, IE jayce in jungle tier list, it probably means I don't consider them 'competent' enough for that role, or maybe I just forgot them.

2/22/13
update:
(^) - next to name = gone up a tier
(v) - next to name = gone down a tier


Jungle:
Tier 1: Amumu, Hecarim, Xin Zhao, Vi(v), Jarvan IV(^)
Tier 2: Nocturne, Cho'gath, Lee Sin, Rammus(^), Olaf(^)
Tier 3: Udyr, Zed, Malphite, Elise, Fiddlesticks, Dr. Mundo(v), Shaco(v), Volibear(^), Maokai(^), Kayle(^), Jax(v)
Tier 4: Warwick, Trundle, Skarner, Sejuani, Rengar, Nautilus, Pantheon, Master Yi, Kha'zix(v), Shyvanna(^), Shen(v)


Top:
Tier 1: Rumble, Lee Sin, Nidalee, Shen, Singed, Renekton(^)
Tier 2: Darius, Elise, Olaf, Jarvan IV, Jax, Kayle, Riven, Yorick, Xin Zhao, Wukong(^), Jayce(^)
Tier 3: Akali, Garen, Katarina, Kha'Zix, Kennen, Vladimir, Pantheon, Teemo, Vi, Malphite(v), Irelia(v), Zed(v)
Tier 4: Cho'Gath, Tryndamere, Gangplank, Nasus, Rengar, Volibear, Poppy(^)
Fiora Tier: Fiora

Mid:
Tier 1: Anivia, Orianna, Ryze, Twisted Fate, Kayle(^), Lux(^)
Tier 2: Akali, Ahri, Cassiopeia, Karthus, Kassadin, Rumble, Morgana, Gragas(^), Katarina(v)
Tier 3: Annie, Diana, Kennen, Kha'zix, Nidalee, Pantheon, Swain, Veigar, Zyra, Zed, Evelynn, Syndra
Tier 4: Brand, Cho'Gath, Elise, Galio, LeBlanc, Master Yi, Talon, Vladimir, Xerath, Ziggs, Zilean, Mordekaiser(v), Sion(^)

Don't bother: Fizz, Fiddlesticks, Heimerdinger, Karma, Malzahar, Teemo, Viktor,


ADC:
Tier 1: Ezreal, Caitlyn, Miss Fortune(^)
Tier 2: Ashe, Graves, Draven(^)
Tier 3: Twitch, Varus, Tristana, Vayne(v), Kog'Maw(^)
Tier 4: Corki, Sivir, Kennen, Urgot(v)

This matters a lot on what support you have

Support:
Tier 1: Taric, Blitzcrank, Sona
Tier 2: Leona, Lulu, Nunu, Thresh, Zyra
Tier 3: Janna, Soraka, Fiddlesticks(^), Nami(^)
Tier 4: Nidalee, Alistar(^)

Don't bother: Karma, Kayle, Lux, Zilean

Translation:
Tier 1: These guys are godly. They are amazing. You want these champs on your team, end of story. They may have some bad matchups in lane, but whatever. These guys rock.

Tier 2: On their own, these guys are still pretty damn powerful. You may pick this character to counter a tier 1 pick. These guys can carry just as hard and contribute just as much as tier 1 characters.

Tier 3: These guys are still very decent, but they're a bit more niche. You would probably only pick this to counterpick, and if you pick it into nothing, you might be in trouble. Most of these characters can contribute quite a bit, but it may take more effort to make them work.

Tier 4: These guys really don't have much in their kit that makes them better than anyone else. They are EXTREMELY niche. With an extremely skillful hand, someone can master this champion and still do tons, but if they devoted that much time and effort into a t1 or t2 champ, they could do way more. They aren't dodgable necessarily, but you won't be excited to have them on your team. It's VERY unlikely they will carry or do anything important. Pray they don't feed.

**** tier: stay away from these trolls. If you play any of these champs, stop immediately. These champions are such **** that you will forever be fighting an uphill battle against your awful kit. Sure, you can contribute and maybe even win a lane every once in a while, but these champs are just ****. stay away.