Argyle King
Legend
It has to be in the high double digits if not actually over 100.
Part of that is that- inspired by one Mr. Alan Hench- I keep buckets of dice on hand for those who forget theirs. But generally speaking, that's just a symptom!
Disease #1: I'm a collector by nature.
Disease #2: I tend to buy a new set of dice every time I feel particularly inspired by a character.
Similar story here, but my dice are in a fish bowl.
I probably have more d10s than d20s though. As others have mentioned, sets usually come with 2d10. Also, (as others have said) it's easier to find tubes/sets of d10s than d20s. If I had to guess, I probably have more d6s than anything else as they're the most commonly available type of dice, and also because I play both GURPS and Dragon Age; both games use only d6s.