Dragalge - has a cool design, Adaptability is a great Ability, and I like the fact it destroys Fairy-types thanks to STAB Poison-type attacks.
Sylveon - adorable and elegant and I love its evolution method (they should have never made affection and friendship become one stat)
Aurorus - majestic and elegant and has a good movepool.
Heliolisk - cute yet cool-looking, and can also learn Surf.
Talonflame - sleek, the first regional bird that changes typing upon evolving, and Gale Wings is an amazing Ability (there was no need for the nerf).
I also really like: Greninja, Chesnaught, Pangoro, Hawlucha, Clawitzer, Aegislash, Goodra, Malamar, Meowstic, Gogoat, and Xerneas.