The one I have now, the Pixel Fold. Folding tech isn't perfect by any means, but damn if it isn't nice to have a small tablet with you at all times not to mention foldy phone unique functionality, like laptop/tabletop mode or folding it like a book for reading (If only I could get a foldy device with an eink screen, it could be the perfect reading device lmao). The pixel unique features are nice too.
Ofc, there was a love before that, but prior to 2015. The Motorola Backflip, damn I wish they would release a modern version of that one :( not the best keyboard to type on, but it was a physical keyboard none the less
Yeah, I'm on a Samsung fold 4 at the moment, definitely gonna be a Fold user for life unless something even better comes along. Can't go back.
I don't know if my galaxy active 4 was before or after 2015, but I loved that thing mostly for the style and the removable battery. Nice to just swap in a fully charged battery and continue on not being tethered to a charger. I got it in whatever they officially called the turquoisey color that year. Usually they were just called "blue" despite very much not being blue, ever. The back panel was so pretty.
Edit: looks like it was released in 2013, but... I still had it until around 2017... so it still counts right? Ah wells, I'm gonna pick it anyway, you can't stop me!