This is a hard one for me, there's at least 1 game I like from every genre.
I don't know if I have any particular fav, but there are multiple genres I go back to. So I'll try-
3D metroidvanias (Metroid Prime, traditional 3D Zelda, Resident Evil)
VR Horror Games (I love the immersion)
Openworld/Adventure
Action Games (OOT ones like Bayonetta)
JRPGs
Nintendo Platformers
Nintencore (I know it's not a genre, I just made it up lol, but Nintendo also makes fun games and distinctive enough to recognise and group together)
Rare Hybrids (Metroid Prime)
AAA games with high end graphics, cutscenes, characters, story, etc.
Fun physics-based games.
Sorry for making a list. I always fail to come up with one answer in VGChartz threads. I did this in another thread recently for my fav Wii game. I think I written between 10 and 20 in a massive list lol :P
I have (or have/had in the household): ZX Spectrum, Commodore 64, Amiga, NES, Sega Master System, Super Nintendo, Sega Megadrive, Gameboy, Playstation, Nintendo 64, Windows 95, Gameboy Colour, Windows 98, Sega Dreamcast, Gameboy Advance, PS2, Gamecube, Xbox, Windows XP, Nintendo DS, Xbox 360, Wii, PS3, Windows Vista, iPhone, Windows 7, 3DS, Wii U, PS4, Windows 10, PSVR, Switch, PS5 & PSVR2. :D
and I Don't have: Magnovox Odyssey, Any Atari's, Any Macintosh computers, Sega Gamegear, Virtual Boy, Sega Saturn, N-gage, Xbox One, Xbox Series X/S, PSP, PSVita & Andoid Phone. Plus any non-mainstream consoles/platforms I haven't mentioned.