Enjoyed Atari 's Crashday a lot, I host the Master Server since end 2009.
CRASHDAY - PC Online Multiplayer game free download here [onedrive.live.com] (full & legal us1.2 version ) or watch short intro.

Due to a severe nerve pain illness I got to spend a lot of time in Need for Speed: World. Had a lot of fun without the need to race, loved the open freeroam / World and easy socializing, shame EA ended it.

TDU2 's free roam & open world is great, shame the number of online players reduced and server is not stable.