I like a lot of series because I've played on a lot of different game systems. Here's most of the series I like:

• Mario
• Sonic
• The Legend of Zelda
• Kirby (♥)
• Super Smash Bros
• Tamagotchi
• Super Monkey Ball
• Bubble Bobble (♥)
• Pikmin (♥)
• Mother
• Pokémon
• Starfy
• Rhythm Heaven
• Rocket Slime
• My Sims
• Mega Man
• Metroid (♥)
• Rayman (♥)
• NiGHTS
• Animal Crossing
• Splatoon (♥)
• Undertale
• ARMS
• Cuphead (♥)
• Ristar
• Streets of Rage 2
• Freedom Planet
• Shantae
• Starfox
• Bomberman
• Kid Icarus
• Skullgirls
• Trog
• Ever Oasis
• Cookie Run
• Hollow Knight (♥)

Probably some others I can't remember right now...