I use a G25 to play rFactor and rFactor2, F12010, and Gran Turismo 5. The wheel is mounted on a WheelStand Pro which is nice. rFactor feels a bit slippy especially in the rear of the cars, but it’s pretty good if you like hyper-prepared cars for your sim. Gran Turismo is just fun and very pretty to look at. rFactor2 is still in beta, so some days you can play and some days you can’t. The online portion of rFactor is good, and some people have serious events with it, including endurance races.
I’ve not seen anyone do autocross tracks for it, but I’d be curious to see one.