PixelJunkMonsters. The unique songs there are very good for ringtones and alarms.
Circle Sketch Fighters has been my since I got my first cell in 2009
Not one that you like too much, your brain will start associating it with a call instead of the song whenever you hear it elsewhere!
I bound the Ace Attorney save game jingles to my coffee maker timer. Now every time I replay those games I reach for a cup.
I’m currently sporting Guile’s theme from Street Fighter 2.
I quite recently switched from Zelda BoTW dragon music to the Gameboy version of Super Mario Land’s first level music and I love it.
Barely counts as retro but I have a friend who’s had the in-game ringtone from Saints Row the Third as their real life ringtone for over a decade now.
Always funny when someone new hears it for the first time and asks about it.
NES Tetris Music C.
