Let's see...
P2D (XR-E Q5)
PD20 (XR-E Q5)
PD30 (XR-E Q5 & R2) x4
LD20 (XP-G R4) x2
I started off with P2D, and it still works, albeit with a slight inductor whine. Then came PD20, which, I must say, is the best looking Fenix light in my opinion. Unfortunately, I lost the thing somewhere in my house, and I can't find it. Four PD30's after I realized I needed something with a little more punch, two Q5's and two R2's. Gave one to my mother, and the other three to my friends. My mother still has hers, and it still shines bright. I can't vouch for my idiot friends, however, because they all lost theirs. After that, I invested in two LD20's as gifts, one for a friend who works for MTA and the other a Navy MP. The one I gave to the MTA dude died due to faulty clicky switch--ended up giving him the IlluminaTi C1 that I had on my keychain as a replacement. Navy MP still uses his 'til this day, and he loves the thing.
I haven't bought another Fenix light since. Their new designs just don't seem to catch my attention. I was interested in PD31, until I found out about the vaunted ring problem. I might go for an updated LD10.