As a child I did ballet, modern and tap. I gave up modern and tap as a teenager but kept up ballet until I was 18 and went away to uni.
At uni I took up ballroom and Latin and did that all three years I was in Sheffield, then took it up again for a year or so when I first moved to London.
Salsa I've learnt for... probably about 2 years, all told, but with gaps. I'm dancing salsa again at the moment.
Plus random short-lived attempts at English/ Scottish country dancing, "Ethnodance" (odd course I did in Austria where we learnt things from around the world), merengue, non-acrobatic rock and roll and (for one routine) Chinese dance.
I think that's it.

I have never seriously attempted hip hop because I just can't get the feel of it at all! I do slightly wish I could have tried to take up break-dancing as a teenager though, just because it looks like so much fun... I'm definitely not brave enough for it now!
Out of curiosity, did anyone take up ballroom/ Latin due to Strictly influences or did people find Strictly after starting ballroom and/ or Latin? Or did the two co-incide but not really relate to one another? I started to take a real interest in Strictly only after I started ballroom dancing, although I'd seen little bits of it before.