League Of Legends Wiki - LCS

LoL esports represents professional League of Legends on a global scale. Primarily it includes the five major professional leagues from around the globe:
North America: North American League of Legends Championship Series (NA LCS)
Europe: European League of Legends Championship Series LCS (EU LCS)
Korea: League of Legends Champions Korea (LCK)
China: League of Legends Pro League (LPL)
Taiwan, Hong Kong, and Macao: League Master Series (LMS)
These leagues, plus international qualifiers from regions not represented above, feed into the annual World Championship.

A couple of teams who compete in the World Championships are:
Fnatic
Origen
Edward Gaming
SKTelecom
Flash Wolves