I do a few different types of riding:
Mountain Bike - Purely XC. Mainly I do faster, non-technical trails. I do a lot of distance riding, generally 20-30 miles on a normal outing. Sometimes 50+ miles. My longest ride on the MTB has been 62 miles. I'm out in AZ, so it's usually sunny, dusty, and dry trails. I do a couple of group night rides every month as well which are super exciting.
I've done a few races over the past year and have a few more planned for the next 9 months including a 104 mile endurance race (Barn Burner in Flagstaff, AZ), a 12 hour team race (Dawn to Dusk in Phoenix, AZ), and a 24-hour team race (24 hours in Old Pueblo in Tucson, AZ).
Road Bike - Casual riding, but I have done some racing and charity rides. I typically ride either shorter 10-15 mile rides with the wife, or 35-60 miles solo rides. My longest ride has been 96 miles.
I have a race/charity century this coming weekend!
Spinning/Stationary Bike - I do spin classes at the local gym 1-3 times a week. They kick my butt, but have been the single best thing for my fitness and strength. The gains in my climbing and endurance has been huge. I highly recommend it. I also have a set of rollers that I've used a few times, but not much since I started spinning.
Out of all this riding, the MTB is my favorite And the road biking and spin classes have been all for the purpose of improving my MTB game. Mostly for this 104 mile race coming up in September. I didn't complete it last year (2 of 4 laps, 52 miles) for a variety of reasons. I hope to do much better this year. I'd be ecstatic to complete it so I'm working hard.
And building a capable bike!