There are a ton of brands and I got a random knock off so I can only report on that one. I would recommend putting some thought and research into what size you think you'll need. I got a 58mm printer and I'm realizing it's quite narrow.
Also you might want to consider the size of the printer itself. I bought a open-box new printer off ebay and the seller's photos didn't give any sense of scale. I was surprised how big this "mini" printer is. It's about the standard size of a printer you'd see at a grocery store, so I don't think I'll be keeping it on my desk.
In the US my impression is that printers marketed with a size in inches are quality printers from reputable brands but bottom feeding Chinese printers are marketed with a size in mm.
There are many similar models from other companies; however, while Bluetooth is advertised as its primary connection, this one also has a USB port, which works with Linux!
Bluetooth also works, but it was too unreliable for me. I ended up using Claude to write a small CLI tool which prints via raw USB: rock solid and simple.
I'd very much recommend a second-hand Epson TM-M30 if you can pick one up for cheap. It prints at 203dpi and can output true grayscale (multi tone) without dithering.
I have one of those AliExpress ones that look like a white box with a colored circle on one side, stylized to look like a cat. They go for a few bucks used in the secondary market. I wrote a simple webapp for it to avoid using the bulky official app, it uses the web Bluetooth API (Chrome only sadly): https://purrint.github.io/
Some people already did that, there were bits of Python and Processing code lying on GitHub I found by searching the Bluetooth device name. I just had to convert that to use web Bluetooth API and build the app around that.
I got the Phomemo M02 Pro and have liked it alright for printing out playtest cards on-the-fly. Claude did manage to replicate an integration someone else did the hard work of working out w/ dithering etc, but the native app's fidelity & speed has been better for my use-case, at least
For daily to-dos a generic 58mm Chinese ones is probably enough. For pen and paper stuff I highly recommend going with anything 80mm, as 58mm can be too narrow...
Search "58mm usb thermal receipt printer esc/pos" on Amazon and you will find various generic models
Also you might want to consider the size of the printer itself. I bought a open-box new printer off ebay and the seller's photos didn't give any sense of scale. I was surprised how big this "mini" printer is. It's about the standard size of a printer you'd see at a grocery store, so I don't think I'll be keeping it on my desk.