These aren't in any particular order, because, you know, horses for courses.
Leica M9-P: it's my "magic camera," as my family says. Every time I pick it up, I feel the responsibility to up my game to match the Leica legacy. Goofy and romantic and mildly delusional, I know, but hey, the placebo effect is real!
Polaroid SX-70, original version. Thanks to the Impossible Project I can use it again, even if it's nearly as expensive as shooting with sheet film. I like to shoot portraits with it, photograph the SX-70 photograph, and then give my subject the original.
Olympus XA, original version, bought brand new by my dad when it came out. It fits in my purse. It was a gift from my dad. It makes fantastic photographs. It's fun to use!
Leica M4-P. What can I say? It's just the right weight for me, I can use it with all of my M lenses, it's gorgeous, it fits my hand like a well-fitted glove, and it's the camera that saved Leica. I love it. And I got it got $600.00US. I usually keep a '74 Jupiter-8 50/2 on it ($30.00US at a camera show), and that combo is kind of magic.
Fujifilm X100. It's just like my Canonette QL-17 GIII, only digital. It's magnificent, in an understated way.
I've done loads of work with my Nikon F3, but you know, it was a workhorse, but I'm just not that fond of it. I preferred the OM-2 that one of the newspapers I worked at issued me. So, add the OM-2 to my list of favorite cameras. (Boy, I buried the lede on that one...)