It's so hard to think of only 3 titles that are likely to be ported, especially after the rumor we heard a few months ago about Bandai working on several games for NX, one of which beeing Smash for launch...
I think Smash is a given so we now have:
-Zelda
-Smash
The other two could be: Super Mario Maker, Pokkén (developed by Bandai), Xenoblade, Splatoon, Star Fox, Tokyo Mirage Sessions and maybe a couple others.
The games I expect to not be ported are: MK8, SM3DW, NSMBU, Captain Toad, The Wonderful 101
If I were to name 4 games (granted Emily might not know about some extra portings) I'd say:
-Zelda
-Smash
-Pokkén/Xenoblade
-Super Mario Maker
Edit: OH, I just now remembered, Xenoblade was downgraded by Monolith to run properly on WiiU, meaning that most of the work would be done if they decided to port it, much like SMM...