I have 12 Briar and 1 MM Corn Cob at the moment, which gives a great rotation. They range from cheap basket pipes and seconds to a Northern Briars hand made beauty, but they all get roughly equal usage. I'll no doubt add a few more for Birthdays / Christmas as you can never really have "too many"!
Have three racks full now: a 12 count, a 10 count, and an 8 count. Two clays in the original box they were shipped in. Two cobs that have permanent residence on the bottom shelf of the table in my game room. Two more pipes that need repair, one that needs restoring, and I just made a huge score off ebay for a dozen more pipes. 49 total as of right now, but I think that there are a few pipes in the ebay lot that I will be selling on here once I get them cleaned up.
Right around 120 now. But this includes an old dealer case of unsmoked Israeli Alpha's (30 pipes) and does not include a box of 30 others that are ready to sell. I sold off 60 others last Summer. Whittling down the collection to probably 60 that make the cut as exellent smokers. Then - one in, one out.
I actually have 30. I forgot that I had a really beat up Kaywoodie that I plan to fix laying around. I was also just given a pipe by another member. So now it's 16 briars, 2 metal with briar bowl, 1 meer-lined, 5 meers, 2 gourd calabash, 1 metal with corn cob bowl, 1 clay, and 2 cobs.