I believe Halo
Who are the most skillful gamers in the world... MLG players. What game is played the most in MLG for 10 years running...Halo.
Say if a person shoots at you first you have time, if skilled enough,you can overcome the odds and kill him. Not who sees who first. Hence the armour.
Halo starts you off with the same weapons...Ergo everyone is on equal footing. It is how you use those weapons is how you succeed. It is about about skill, strategy &(sometimes teamwork).
The most known MLG Pro's are Halo players and have great montages.
Halo was on the MLG circuit long before any game you know.
League because League of Legends currently is the most played PC game with 10 million daily players and 67 million monthly players. Esports has also completely evolved due to League of Legends. The Season 3 World Championship was watched by 37 million people.