With my K1, the lenses I generally use are my 28-105, my 100mm Macro DF A , F 2.8, my 50 F 1.4 and Macro 50 F 2.8.
I also carry around two ASP-C Limited lenses, my 40 and my 70. For these, I set the K1 to Full Frame and I like these lenses, even though some might say they're ASP-C...why use them.
I find that in the past couple of years I've gravitated towards my prime lenses. I find them interesting to use, albeit a zoom has more versatility. The nature of a zoom is wonderful to use, but I also find I like the challenge of a prime...when it comes to composition.
One lens I plane to use is my Pentax 'A' 35-105 Macro zoom. It's old (I bought it new, Dec. 1984) , heavy, manual focus, but I've loved the pix I've got from this lens. Some of my best ever and this lens is probably my all time favourite Pentax mount lens.
I generally use my Sigma 150-500 , although it is a full frame lens, with my ASP-C K-5. The K-5 is an excellent camera and gets more 'reach' out of the this telephoto lens than my FF K-1 would be able to.
I'm a hobbyist, an amateur...so unlike a pro, I'm not faced by a number of constraints and requirements. I'm able to take my time and I don't have to please clients...I'm the only client.