Sadly enough Euro Truck Simulator 2. Got it years ago and never touched it until recently. Ended up liking it so much I bought all the map expansions and a Logitech G29 with the whole H shifter, pedals setup. Never thought lugging a trailer across Europe could be so satisfying but there you have it.
Just totalled my BMW 320d M Sport.....:(
Now got a Skoda Superb SE L Executive - which is really nice - its an Audi A6 underneath but nooone hates you for being an Audi wanker.