Best Teams atm: 1. Fnatic 2.Navi 3.Luminosity 4.Envyus 5. Astralis.
Fnatic Players: Olofmeister, KrimZ, Flusha, JW, and Dennis.
NaVi players: Flamie, Edward, GuardiaN, Zeus, and Seized.
Luminosity Players: Fallen, Coldzera, Taco, Fer, and FNX. ( in my opinion )
Envyus: Ki0shima, Kenny S, Happy, apEX, and NBK
Astralis: Karrigan, Dupreeh, Device, CajunB, and Xyp9x
Those are the best teams. You can find each player's individual role in the team using this website. http://wiki.teamliquid.net/counterstrike/Main_Page. This also provides a lot of info on the teams too.
http://www.hltv.org/ranking/teams/ (Team Rankings)
This is not meant to insult you but the Optic CSGO team isnt very good compared to other teams. They are in my opinion tier 2 NA team.