What is the trick to looking objectively at your roles, and finding out what you should be playing?
I love mid.
I love being the person who does a buttload of burst damage and has the possibility of getting lots of kills and completely turning team fights. On the other hand, I have noticed the more games I jungle (pretty much maining Volibear and Vi there) I tend to win them. My least comfortable role is ADC because I go too hard for kills and most of the time it doesn't work well-- support I can do but I don't like it because when my mid and ADC sucks I get pissed because there's nothing I can really do. I've noticed though that even when I smash my lane mid, I still lose games. I have always really liked Annie, but I'm starting to think she's pretty much a one trick pony with the flash ult. It can be really good, but when your team doesn't follow up it's often a recipe for disaster.
Anyways the thing is when I play Jungle I tend to win more games. When I am Volibear I usually don't get a gank in until lvl 4 and have a difficult time deciding when to do dragon. Late game he's just a freaking beast but almost every time I play him I'm usually around 5-0-5 going mid to late game and my team is usually doing well unless one lane just feeds out of their mind. I have problems ganking bot with him too, I just feel like he's a slow bastard sometimes and is easily kited by someone with a slow.
TL:DR; How do you choose which role you should be playing? The one you win games with, or the one you enjoy the most?