What retro handhelds are the best value?

I've been interested in the retro handhelds I've been seeing by companies like miyoo and AYN for a while. I'm curious to see this community's thoughts on the available options. I'm thinking of asking my girlfriend to get me something like the Miyoo Flip V2 for Christmas. Basically what I want is a small handheld that is easy to bring with me everywhere and take out and play with for a few minutes while I have breaks at work. My budget would be around $100, but I'd be happy to hear thoughts on the more expensive options like the AYN Thor.

I do already have a steam deck for home, but I'm hoping for something a little more portable for playing around with older games.