>>287161050
Depends on what you're looking for, but I prefer Assetto. PCars 2 has better VR support and a better career mode. Assetto has a ton of mods, and I like the actual driving better in it. You can just wait for the Assetto with all the DLC to go below $10 again and pick it up too.
I should probably try hosting PCars 2 sometime, but I don't know how many people actually have it.