I love my gear but I gotta say the coolest thing I've ever bought was every pair of Vans Skate Hi's and Old Skools since the mid-eighties. Oh yeah, and a first pressing 7 inch Black Flag, Nervous Breakdown which I still have.
Coolest thing (excluding trips, plane tickets, etc.) I ever got (didn't buy it myself) was a leather bomber jacket from my mom as a HS graduation present. I wore from spring to fall for more than ten years, until it finally wore out. It's still sitting in my basement because I keep saying I'm going to get it repaired (not sure it can be repaired, patches wouldn't look right on it, entire pieces would have to be replaced).
Other items that are high on the list:
(2) the very first walkman that was ever mass marketed in the U.S. I must have mowed 1000 lawns with that thing clunking against my side. The sound was sooo much better than even the stereo my parents had at the time.
(3) a ticket to Game 6 of the Bulls/Lakers NBA finals (first championship) in 1991. I grew up in Chicago, the ticket was a gift from some long time family friends. The series finished in 5 games, so I never got to use it. Still have the ticket.