I'd also love Next Level Games to make another Mario Strikers. The Strikers series is one of the best Mario spinoffs — second only to Mario Kart, IMO.
Mario Strikers Charged, in particular, was incredible. Just loads of style, humor, and rainbow-hued darkness. Everything about it was SO COOL — from the sound of rolling thunder on the menu screen, making you feel like you were revving up for a fight... to the bloodthirsty crowds and creative stage gimmicks, like cows flying across the field during a storm... to the delightful antics of the characters: Waluigi's crotch chop, Daisy licking her finger and touching her butt in a sizzle of steam, etc.
Strikers is a game where every character is "The Luigi Death Stare." It's hilarious. The action is intense, and the atmosphere is off the charts. I want another one! A game like this, where the camera is drawn back, would benefit greatly from HD resolutions. Also, imagine feeling every bone-crunching tackle with HD Rumble!
I really, really, REALLY want a Mario Strikers: Third Strike. But barring that, I'd also happily accept a Luigi's Mansion 3. A new LM with Switch's graphics would melt minds.