Started in '78 (at the tender age of 12) with a K1000 and shot
so many rolls of film I can't even imagine. Most 12 year olds spend their allowance on baseball cards or comic books. I spent mine on Kodachrome.
My dad wanted me to learn how to use a camera, f-stops, focus, DOF, the works. And boy I'm glad he did.
That K1000 took all the abuse I could hand it and it
N-E-V-E-R let me down. I dropped it (more than I care to admit). I jostled it for miles and miles while I rode my bicycle with it jammed in a gym bag. I left it in my Dad's trunk in sub-zero weather (he took the car to the airport for a business trip for 2 weeks - it was like someone took my right hand). I hiked with it up in the White Mountain range in NH with it stuffed in my day pack with PB&J's, dirty socks, and water bottles in there to keep it company.
Pull it out, turn the focus ring, and push the button.
I had my original K1000 stolen in a house break-in (which all these years later still hurts) and replaced it with an ME Super. I was nervous. It was more advanced, had WAY more buttons and controls than my "K". It was a beauty, but would it be as reliable?
Yep.
I still have it and we'll be celebrating our Silver Anniversary together next year (please no cards or flowers necessary

). It just works. I've had it CLA'd a couple of times, changed the batteries and pulled roll after roll out of it.
They are built like tanks, reliable, and capable, I couldn't leave the Pentax Nest.
I bought an *ist DS (quite possibly the dumbest names for a camera line IMO) back in '05 for a trip to Yellowstone. It's got over 12k shutter cycles on it and it is now being used by both my son and daughter as a way to learn photography. Its still going strong and being heavily worked out by my 13 and 11 year old.
I bought my K20D late last year (kind of on a whim) and like the 3 before it, it just works. With it's metal frame and its weather sealing it feels like it's up to the same vigorous use my other Pentax cameras got. And so far, so good.
I only hope that Hoya does right by Pentax and keeps them alive and relevant. I think (and yeah, the Nikon and Canon guys will pummel me for saying it, but so be it) that Pentax made and makes some of the finest optics that are on par (or even better) than those offered by the Big 2. Not the broadest selection. Certainly not the most popular in terms of sales figures, but still some exceptionally fine glass.
Sorry for the long winded response, but thanks for letting me trip down memory lane.