Going to stick with portable systems, because a box is a box is a box, even if some are cooler than others (PS2 slim with attached screen, and N64).
#3 Gameboy Advance SP
Loved the compactness of the clamshell design. So much more portable than other systems at the time.
#2 Steam Deck
Windows games on a Linux handheld, plus it runs old games that Win 10 can’t.
#1 PlayStation Portable
This was and will always remain my favorite gaming system. So many great games, movies, a cool disc/cartridge hybrid media format, SD card support for all sorts of stuff, custom firmwares… man, such an amazing system.