Hmm Super Mario Odyssey is a no brainer as is most of the first party titles. Mario Kart 8 deluxe is great, mario party, The Legend Of Zelda Breath of the wild is probably in my top 5 games of all time though, it's a must if you have a switch. The Xenoblade games are great, the series as a whole is amazing going all the way back to the Playstation. Fun fact Xenogears(the first game in the series) was originally planned as Final fantasy 7.

Im sure you already know but if you dont have smash brothers for the switch then what are you doing with your life? Its the most iconic game ever made