Sim:
rFactor
rFactor 2
Live for Speed
iRacing
pCARS Q1 2013
http://www.wmdportal.com/
Assetto Corsa Q4 2012-Q1 2013
http://www.assettocorsa.net/?lang=en
netKar-Pro
http://www.netkar-pro.com/main/
Race07 + exp: WTCC, WTCC2, GTR Evolution, etc.
GTR2: great FFB IMO, 2006 game
GT Legends: same as GTR2
Simraceaway: F2P, currently in BETA
http://www.simraceway.com/
Richards Burns Rally: Best rally game ever
Real:
SHIFT 1
SHIFT 2 patched and modded only
Auto Club Revolution: F2P, currently in BETA
http://autoclubrevolution.com/en/
F1 2010-2011
Wrc 2
http://www.wrcthegame.com/
Real Arcade:
GRID
DIRT 1,2,3
About pCARS: You can become member and try the Builds currently in Pre-Alpha / Alpha, when the game sells you will get a share of the sales profit. Membership start at 10 euros. I recommend to become a member since you also gain access to the private forums where you can see and read how the game is made, share your opinion with the Devs, and help make the game.
About Simraceway: Currently in BETA, there are few tracks and only 2 are graphically good, but since it's F2P there is no reason not to try it.
About Auto Club Revolution: If you are looking for a sim experience look somewhere else. Graphics are Ok, some tracks like Spa, Infineon, or silverstone look quite good. But some parts of the track itself are not accurate, like some curbs at Spa, Eau Rouge, etc.
I would say this is a Realistic game (not sim) closer, but not in the same league, to GT5 or Forza, i tried the game with the 360 pad, and it bothers me that there is no deadzones, speed sensitivity, etc customization. I really don't feel comfortable with the current controller setup. Rumble is set really low to the point it doesn't exist (maybe a bug).
Online races: so far there is too few people so you are always waiting in the lobby until is full or almost full, half the time the game refused to load the race. I can't say it's bad because it's in BETA but it can improve a lot. Once the race start you realize all cars, even if they are the same, are different due to engine, tires, gearbox, etc upgrades. So you end up racing against no one since slower cars are left behind rather fast, while at the same time you are left behind by faster cars, it remind me of GT5 online, waiting more time on the lobby than actually racing, freezes, and crappy races.
How it works the currency system: You start with a free Opel Corsa, the more you race either online races or time trial, the more credits and experience you earn, you can upgrade your cars with those credits, some few special parts (slick tires, some rims) cost real money. New cars are bought with real money, although once you unlock a certain Xp level, they give you a free car (Mazda RX 7).
I think of this game as something you have when, i don't know you are bored of all the others great games you can play like pCARS, Rfactor, RACE07, GT5, Forza,...(insert game name here)... etc. This is more aimed at casual public, teens, etc.
So far there are 5 tracks and and like 50 cars.
i forgot, the is no onboard camera, that alone is a huge let down.