My first was a 830 Trek hybrid back in the 90's. I had two sets of wheels and rims. Knobbies for trails and slicks for pavement. I rode the crap out of that bike for a few years, then got distracted, can't recall by what, and stopped riding. I still have it, but sadly I let it sit out in the desert for the last ten years. I thought about restoring when I decided to get back to biking about a month ago. The frame is nearly perfect and all the components still function. The tires, seat, and grips are shot to hell. The LBS quoted me about $250 to restore it. Maybe someday. It deserves it, even if doing so makes no financial sense.
My second mountain bike is the Specialized Hardrock that I bought just a couple of weeks ago. Getting back in the saddle after all these years, and with SEVERAL extra pounds has been challenging, but rewarding.