The Mario Universe has a variety of characters, with many of them staring in their own successful platformers and spin-offs. One thing I liked about the GBA/GCN and DS/Wii days was that Nintendo took a lot of risks with the cast, putting Mario and his friends into a variety of unconventional and experimental games and spin-offs. Mario's brother Luigi took the staring role for the first time in Luigi's Mansion. Mario himself got a water pack on a Tropical Island, and was then later sent to outer-space. Wario started his own game company and subsequently, a unique series of puzzle games revolving around 5-second games. Donkey Kong got a rhythm game and an action platformer, both controlled with a pair of bongos. Yoshi got a platformer using a unique tilt-control mechanic. Princess Peach also got a staring role with Super Princess Peach. And this was just a taste of the weird stuff Mario and his pals were up to in this time.
But somewhere around the Wii U and 3DS era, Nintendo began playing it safe with the Mario pantheon. Not only did Mario's main platforming games reverted to just using a generic Mario obstacle course style, but all the weird spin-offs that he and his friends got, either vanished, were overly sterilized, or mangled beyond recognition. Really the only exceptions were Captain Toad and Yoshi's Wooly World, maybe Luigi's Mansion Dark Moon.
With the success of Super Mario Odyssey and stuff like Mario & Rabbids and Super Mario Party, I'd like to see Nintendo take more risks with the Mario Universe again, give me more weird spin-offs with characters like Daisy and Bowser.