It's kind of interesting to think about which of the many many features Rebels have you really use. I expect a wide variance, but although I shoot a lot and have for many years, I think I only use 25% of the features on my 450D.

I almost always shoot in TV and RAW and use single shot.
I often use the 2 second self timer when shooting on a tripod.
I use the exposure compensation a lot.
I use the depth of field preview fairly often.
I change the iso quite a bit.
Every now and then use manual exposure.
Occasionally I use exposure lock.
Lately I manual focus most of the time.
Once in a while I use flash exposure compensation, but not often because I rarely use flash for the kind of things I like to shoot.
I have occasionally used manual white balance when shooting under halogen lights.
I should use mirror lockup more, but I have not gotten into the habit of it.

What features do you use the most?

Jim