It is a close call between my two, Minecraft or Roblox. I have to hand it to the Roblox designers - they created an incredible gaming environment that is 100% a money maker - everything about it needs extra purchase to upgrade character - access VIP - they are literally minting it in. The platform upgrades constantly and improves and runs really well so I don't really feel upset my 7 year old regularly needs a Robux hit to pimp up his character - but I feel compared to stand alone game manufacturers selling a one off game either physical disc or download - Roblox are on a constant money train - and even better they get other people to make the game environments for them - such a genius move it makes me wince a little in pain.