DiRT Rally is probably my current joint top, it's the only one with a comparable sense of immersion, but GTR2 is my all-time favourite and still great for perfectly tuned endurance races against huge grids with good AI.
Stock Car Extreme for me. I want to say rFactor 2 as it's a great drive but sadly it lacks content of interest to me, particularly tracks. I know there are rips of pretty much any circuit out there, but I'm only interested in the quality stuff. SCE is just a great all-round product, although showing its age graphically.
rFactor 2, I just feel so connected to the road, the cars react as I would expect them to react. I had the pleasure of driving a Ferrari 458 Italia a few months ago at speed on a track. I was able to jump in that car and drive fast - well, as fast as I could within my senses. Many of the cars in rFactor 2 feel the same, being able to push with little prior seat time. But rFactor 2 is lacking in a lot of other ways that it isn't my only go-to. I wouldn't added GSCE also if I could have. As far as a racing game in general, then its Project CARS and R3E.
rF2, because it actually gives the best and most complete package for league racing. (Not counting iRacing or older sims here) In my opinion the FFB in rF2 is great out-of-the-box (without the need to tune it like hell) and very communicative about what the car is doing. And it's the first sim i know, where tyre management becomes a very important role. You'll get punished hard with massive tyre wear for spins or drifting around every corner. Once you've driven with a hugely flatspotted tyre and the extreme FFB vibrations drove you mad, then you know, what you've done wrong. It's a very consequent route, and i wish more sims would penalize abusive driving. And of course ........ RealRoad ........ what a damn great and unique feature in rF2. This changes everything during a race.
Voted for GSCE and Project Cars, simply because they are the most complete sims for single player. I would easily vote for Assetto if their AI was any good and they had a better career mode.
im honestly not sure where most of my hours are going lately. it feels like a pretty even split between all of them. maybe least time in AC or SCE lately, but i think theyre great.
Lately it's been between R3E and DIRT Rally (biggest surprise ever!!!), although I still run GTR2 just for the 90's supertourers and the SuperGT mod. I'll probably get one of the other newer simulations after I finally save up enough $$ for a new wheel.