I recommend the Chinese handhelds too, I only have a Retroid Pocket 2 (too old), Anbernic RG351V and a Miyoo Mini V2, I only use the RG and Miyoo, the later is great for simple games/quick burst but due the lack of wifi antenna it is not possible to use Retroachivements with it… which it is possible with the RG351V, also the Anbernic has quite the better hardware without a question.
Notice all these aforementioned handhelds would only give you a pleasant experience up to PS1 (minus Saturn), so if you want a handheld that can at least give you PSP, Dreamcast and N64 I’d pick an Android based Retroid Pocket 3+ Anbernic also have some capable models for this. it is worth to mention that if you have a relative new Android phone you already have a capable emulator with you all time, you’d only need a holder or a telescopic joystick to enjoy an almost endless library of games (despite having a PSP I finished Persona 3 Portable with my phone and a Razer Kishi controller).