Euro Truck Simulator 2
After a poll of ETS2Downloads, there are 200 votes for this map and it's the best, of course. The next version is Promods Map with 120 votes.
I saw this map the first time in 2012, when it was just a small beta map with a few cities. After 2 year, with a lot of changes, till now, Trucksim Map is the best map for ETS 2 with a large number of ciities, trailers and other objects in game. It's better than a DLC. It's like a real world. All roads in Europe and many roads in the North of Africa have been added in the latest version of this map. With a biggest community, this map is more and more better!