Assetto Corsa was one of the games I wasn't really sure what to expect of. I was pleasantly surprised!
Over the years I have played a couple of racing-simulators including rFactor and Grand Prix 4. But This is the first sim I already enjoyed without installing any mods.

The handling model in the game is fantastic, during the past couple of months I have been playing Codemasters F1 games quite a lot. I mastered those with no assists and legend AI, but when I first got into Assetto Corsa I was again reminded of Codies not making real Racing-Sims anymore. This game was just a huge throwback to the time I played sims only, around 4 years ago.

It is really statisfying to get faster and faster in this game. the more you understand the car, the more you feel the need of pushing your lap times.
Unlike some other games, it is really possible to get more into a car and feel that statisfying progression you make.

The car list in this game isn't as impressive as the one in Project Cars, but I have experienced Project Cars as hectic with all the different cars, this is a way better concept. Same goes for the tracks, There isn't a enormous amount of tracks in Assetto Corsa, but that makes you want to master every single one of them.

In the first couple of hours there isn't really a need to install mods, but when you want to have some difference between the F1 Cars like me, start with downloading some skins, it's an easy and rewarding way to get into modding the game, but you don't have the problems that cars don't work.
If you do want different cars, just search for them, but keep things organized.
One thing about mods I cannot recommend are the track-mods. Most tracks I found are really bad. There are some good ones, like circuit de la Sarthe and Hockenheim 1988, but most have holes to fall through or don't allow you to do a race.

I really recommend this game to anyone wanting to get into sim-racing, but it is nice to have a wheel for the real feel.
The game supports almost everything, including my 16 year old steering wheel!