If one considers all the titles currently available, I think I am Setsuna, Shovel Knight, Zelda BOTW, Fast RMX and Snipper Clips are worth it the most.
The problem is that I am Setsuna and Shovelknight keys for steam are dirt cheap compared to the eshop prices (Like it always is with nintendo's price stability which is a lot stabler than their OSs), Zelda is also on Wii U and many prople won't buy a console for one semi-exclusive game, Fast RMX is also on Wii U so the same reason applies here and snipper clips is probably not that fun in single player mode if it does even have one.
I really try to find a reason to buy a switch even though there are no games that are worth it atm for me with my Wii U.