I love all if these responses! Great amount of diversity, and everything I’m reading is something I’d be like “Yup. I 100% agree with that one.” Crush 40, all the music from the DKCountry series (speaking of which, Nintendo, when will you follow up on Tropical Freeze??), Mario Party, Final Fantasy, etc.

Keep em coming!

The Xenoblade series is packed with incredible music:

Depends.
If it's OST that stands on its own, without actual games, then my pick is Zelda.
If it's OST which is one of the key ingredients for overall feel of games in that franchise, then Interplay's Fallout.

Persona and it's not even close.
And I say that even though my favorite OST isn't from there but the level of consistent quality for 3-5 is just out of this world.

Far too many to choose from, Different styles, genres and vibes that are difficult to even compare.
I have to say, Expedition 33 didn't really do it for me musically. Too "musical theater" for my tastes.

Sure why not.

This isn't a franchise but I recently played Neva so I'll recommend that. It's a beautiful game that is really enhanced by its music.

1. Zelda (3D, 2D, spinoffs, you name it)

Donkey Kong Country
Mega Man (entire franchise; each series has its own memorable tracks)
3D Mario (World for 2D)
Sonic (2D, 3D, Racing)

Of course there are tons of great franchises with phenomenal music, but these are the 5 that have stayed with me throughout my whole life.

I tend to see franchises as an IP with two or more games. But sure, who cares...

Franchise refers to IP which is licensed to other parties. So i dont think it has to be more than one game. In gaming its used in a weird way that usually means mutiple games within one series.

So going by what the word typically means, yes. By the way it is typically used in gaming,  no (although you can include Deltarune here.)

But the more important point is that Undertale had amazing music and deserves mention in this thread.