I frequently play Canfield, a.k.a. Demon. It's what I play more often than not.
I've also been known to play Clock now and then - I have a variant I play while holding the entire deck in my hands, for times when I want to play a game but have no space to play, but when I learned the game, I also learned from the rulebook it was in that the odds of winning are around 100 to 1, so I don't play it too often!
My father was a big fan of Spider Solitaire. Some variants that would be more difficult to play in the real world have become very popular on computers and smartphones - Spider is one of them.