League of Legends is as much a game of strategy as it is a game of skill, and as such can and has been won in arguably the most strategic part of the game- champ select. You might not be able to choose what your teammates play, but you can choose what you play, and no matter what role you're stuck in; there's always a champion that should work for you- it's as simple as figuring out what works best with your personal playstyle.

In my case, I was just playing what everyone was- until I really took a look at my own playstyle and discovered what champions I should have been playing all along. I'd say that this was the most important change that I made which allowed me to carry myself from Bronze to Gold. So let's just go through some of the most common playstyles and discuss what roles or champions would fit the best with each one, in the hopes that it will help you find some champions that you can succeed with.

Passive:

This is the playstyle that I incorporate in the majority of my games, and one that I generally think is the easiest to play as. However, despite it being the easiest way play to the game, it might not necessarily be the easiest to win with. A passive playstyle is one that isn't centered around outplaying your opponents and racking up kills in the early game, but more about farming up and playing well in the late game. If you excel at teamfighting, but are lackluster with your laning phase or just generally have mediocre to subpar mechanics, it might be worth it to give a more passive playstyle a shot. The champions or roles that go best with this playstyle would really be any late-game champion; preferably those that are less mechanically intensive like most ADC's, hyper tanks, or peeling/healing supports. If your positioning is sub-par, and you're more of a playmaker you may want to lean towards those tanks and not any adc's or dps mages.

Here are a few champions that fit this role nicely:

Top Mid Jungle ADC Support Malphite Orianna Mundo Jinx Janna Sion Cassiopeia Master Yi Tristana Soraka Nasus Anivia Shyvanna Sivir Nami

Feast or Famine:

While feast or famine is not necessarily a playstyle that I would endorse, it is still a relatively popular one. In essence, feast or famine is a game of either getting fed and carrying, or losing/going even in the early game and being nearly useless for the majority, if not the entirety of the rest of the game. The champions that best fit this role are any that have a strong early game and are able to snowball the game out of control quickly. These champions are also often highly mobile and require more mechanical prowess than their late-game counterparts.

If you're the kind of player that finds themselves getting early kills or winning your lane often, you may want to check out some of the following champions:

Top Mid Jungle ADC Support Pantheon Leblanc Rengar Draven Karma Riven Zed Shaco Lucian Sona Darius Fizz Nidalee Graves Brand

The Playmaker:

Playmakers are the glue that holds a team together. These players are capable of turning teamfights around with quick thinking or good positioning. If you find youself to be someone who does well under pressure or enjoys turning the tides of a fight you might be the next great playmaker.

Here are a few champions that fit this playstyle and the current meta well:

Top Mid Jungle ADC Support Malphite Cassiopeia Amumu Jinx Soraka Sion Orianna Sejuani Miss Fortune Sona Wukong Yasuo Nunu Tristana  Alistar

The Roamer:

A roamer is someone who spends their early game helping their team out through ganks. While this is a role that is obviously best suited for mobile junglers, roaming is also something that is really strong on mobile champions that have hard cc, insane damage, or sometimes even both.

If you're the type that enjoys roaming and is alright with being carried by your team in teamfights, you might want to check out these champions:

Top Mid Jungle ADC Support Pantheon Leblanc Rengar Lucian Blitzcrank Riven Zed Shaco Draven Thresh Volibear Fizz Nidalee Tristana Bard

Hope this helps you find the right champion for you, good luck!