Way too many of both I suppose, but I bought my first HD DVD before even getting a player (RCA version of the Toshiba HD-A1 back in July 2006). Really good deals were hard to find before late Auguest 2007, so my HD DVD count was VERY slow to grow. However, that Autumn was when BD sales started hitting hard, and HD DVD started trying to keep up. Those sales led to my picking up enough BD exclusives that I felt compelled to get a player (BD-P1000). During that period through CES2008, there were a LOT of great prices for both formats and I took adventage of them.
I've always tried pretty hard to stick to titles that really interest me, as well as with SD DVD and LD (got loads of both.) I've also tried to avoid duplicating titles in my other formats, unless I saw a clear advantage or it was a film I especially like. I've had a few failures in both endeavor's, but not too bad all-in-all

! I'm still open to buying HD DVD given the right title and the right price, but at about 200, it's well nigh impossible for me to find further titles of interest. Whereas, as further BD titles become available, and sales show up to facilitate selective purchase, I continue to partake -- the count having just exceeded my HD DVD collection in the last two weeks.
As I said, too many! I'm just glad they weren't at anywhere near full price, and I fly with used where condition, price, and availability make it feasible!