I have two 2Bs and the original B
At one point I used one with a cheap tiny ass screen as a YouTube box with no desktop environment and a Python script for scraping YouTube's search results and, after making my selection, download a 240p video and launching the video player with X11 (my RPI 2B seriously lacked the horsepower, was only 32bit, and the screen was also so tiny and terrible quality that anything above 240p didn't make much sense either way). But it was great for watching podcasts like the Co-optional Podcast and its predecessors (RIP TB

), RoosterTeeth podcast, Triforce podcast (well this one was always an audio only one either way). But I basically stopped using it once TB passed away since his podcast was the only one I actually liked the most.
The second one had several use cases in its life. First I used it to generate Top 100 list for my tumblr blog that I used to have. I would rank every image I posted on it by the note count and (I believe) I've kept the changes in note counts in a local SQLite database. I think I also used the tumblr API to post a weekly post with thumbnails of the couple most popular images. I can't really remember the specifics since it was around 10 years ago.
Later I used it as a print server so everyone at home could use the printer in my room from their computers and smartphones via our local network. I also had used it as a NAS for a short time but the 2B's 100MB/s connection and the shared USB 2.0 speed was terrible (currently I use the same SSD drive enclosure with my MikroTik router with 1000Mb/s throughput and a USB 3 connection as a NAS).
Now I only use the second 2B as a Git and Pi-Hole server for probably around close to 8 years by now. I know it's the second one since it's still called "printer" despite me not owning a printer for probably close to 10 years kek.
On an un-/related note, the microSD cards in my 2B RPIs were bought in 2016 which means that at least on the 2nd RPI the same microSD card basically ran 24/7 for a decade now kek (please don't die

).