So.. Let's keep this short, I am trying to specialize in one lane and very few champion but the choices are numerous... Can you guys share with me what lanes you like and what champions you play/main and how did you come to that decision/why?
Over the past 2 years I've gone through roles every few months. At the moment, I main mid, because it fits my playstyle. And, that's really what it comes down to - your playstyle.
Also, I main Veigar. 
I like Veigar because of his art style (the fact that he looks like a black mage from Final Fantasy), his lore, and his Ap-Stacking, 100-0 burst playstyle. And dat laugh.
I wouldn't recommend him at the moment though...DFG was a crucial item on him and it just got removed from the game. I'm waiting to see how Riot is gonna balance him out.
I mostly play shock value picks that work well.
For example, Alistar is a great AP tank! He's a great team fighter, and surprisingly, he does very well in the mid lane against skill shot oriented champions such as Orianna. Anytime she goes to Command her ball, just Headbutt her and it will never land.
i play safe cuz i dont wanna be like those cancerous dumb fucks down in bot lane that does nothing but throw games and feed.. d/c and afk ;l which is why i play passive mid lane: malz and ziggs top: nasus, udyr, jarvan jungle: jarvan, udyr
I favorite roles are mid and jungle. I like mid because I like to throw skill shots and have a natural affinity for mages. I'm not too crazy about melee fighters because it doesn't seem to make much use of ability skill shots, more like when to activate a self buff or something. Mid is usually the center of attention though for ganks so you have to be on edge a bit. I usually play Ahri, Zed, or Ziggs mid I like jungle because its an underappreciated role, next to support, and I like to go around and help everyone and don't care about getting a kill myself, as long as my team has an advantage. Also, I'm not directly going up against someone as I would if i were in a lane, so its kinda easier at times. A very unique role it is. I usually go jungle with Hecarim or Nautilus, depends on what our team comp needs.
u dont choose the lane the lane chooses you.
I like to play champs that can really make a difference when used well because I'm pretty aware of what my team needs. I play Lulu and Singed, which are both very mobile and have some up-the-sleeve moves that help me capitalize on various situations.
Just identify what you want to play. Range or melee ? tanky or assasin ? is there special skill that you like to play with ? regen ? shield ? heal ? gap closer ? burst ? dot ?
Then find the champions that fit your preferences and then you can figure out easily what lane they are evolving in.
