Since I've got already got a great lineup. Definitely the DA* with weather seals for my outdoor photography.
Current lineup:
FA* Series Lenses
* Pentax SMC FA* 80-200mm F2.8 ED(IF)
* Pentax SMC FA* 200mm F4 ED(IF) Macro (1:1 magnification)
* Pentax SMC FA* 300 F2.8 ED(IF)
Prime Macro Lenses
* Pentax SMC FA 100mm F2.8 Macro (1:1 magnification)
Zoom (Wide Angle and Telephoto)
* Pentax SMC P-DA 18-55mm F3.5-5.6
* Pentax SMC P-DA 50-200mm F4-5.6 ED
* Pentax SMC P-DA Fish-Eye 10-17mm F3.5-4.5 ED (IF)
* Pentax SMC P-DA 12-24mm F4.0 ED/AL (IF)
* Tamron 28-75/2.8 XR Di
* Tokina AF 80-400mm F/4.5-5.6 Zoom (1st Gen.)
Prime Standard Lenses
* Pentax SMC P-FA 50mm F1.4
* Pentax-A SMC 50mm F1.4 MF
* Pentax-M SMC 50mm F1.4 MF
Last, and certainly not least, I plan to get the "big gun" of big guns - the FA* 600/4. That's being taken care of by the right people...