Good controller for android emulation on a budget, I started off with this one and connected it to my phone (Samsung s8) with the OTG adapter it came with, I've since got
Logitech Gamepad F310 USB | 333 EGP
Gamesir Wireless Bluetooth Mobile Controller Gamepad For Phone iPhone Switch PC | eBay
F310 Gamepad - Console Style - Logitech Gaming
Android] Use Gamepad, Keyboard and USB Memory - YouTube