Who deoes mario like as a friend?

~Luigi
~Yoshi
~Donkey Kong (Well... There relationship may vary depending on the game.)
~Princess Peach
~Princess Daisy
~Rosalina
~Pauline
~A bunch of toads
~Toadette
~Geno and Mallow from Super Mario RPG
~All his partners from Paper Mario
~All his partners from Paper Mario: the thousand year door
~The Pixls from Super Paper Mario
~Kersti from Paper Mario Sticker Star
~A bunch of other characters that I forgot about/too lazy to write about at the current moment.XD

A bunch of toads, his brother, other mushroom kingdom residents

Refer to NintendoFan's list.