Honourable mentions though are - AoE2, C&C RA2, UT 2004 and Lego Racers
Brian Lara International Cricket 2005
International Cricket Captain III
GTA San Andreas
If someone plays please message me, lets be friends
Impossible to say really.
I've played LOL for far more hours than anything else if we are including such games. If not, it probably has to be Witcher 3, or Boulder Dash. Europa Universalis (3 or 4) are also definitely in the running with hundreds of hours played.
Recently I have played far more PUBG than anything else though.