I've got a K 17" Medium Thin Dark. I like it alot. Not too dark at all. Full loud attack with a great rate of decay that doesn't go on forever. Don't buy them online though. I'm on my secound one and I matched it perfectly to the first.
Check out the Paiste Dimensions. They're a really great value. I love my signature series hats and Fast Crash, but in some sizes the Dimensions really stood out, even aside from their great bargain. I've got an 18" med thin crash and an 18" thin China that I bought purely for sound - not for price.
Like someone mentioned, check out Bospherous too. I have a 20" ride I alternate with my 21" Zilidjan Sweet Ride. It's a little tighter with less overtone builld-up. And a great bargain too. Mixing and matching is where it's at. Get out and hit them all and you'll find what you like.