My Top 5 would be:
5: Siesmotoad/Bats or Raichu/Bats
Siesmotoad is probably gonna see less play do to Vileplume and M Sceptile but I think it will still see play with cards like
Hammers, Flare Grunt, and Crawdaunt for disruption and Lugia EX for attackers.
Raichu/Bats will still see strong play especially with Level Ball coming back but I think it will be expected and won't be as strong as it was in Nationals.
4: Giratina/Vileplume
Will see play no doubt with the amount of potential it has with Giant Plant Forest, Level Ball, Wally, DDE, Hammers, Hex Maniac, and Hydreigon EX.
However I think it will be expected as well if it becomes overhyped so I think it'll be another "Pyroar Deck"
3: Fairys (M Gard/Toolbox)
I think it'll be getting a big boost even without Max Potion. I mean Level Ball, Giratina EX hype, Super Scoop Up, Xerneas, Able to run Fighting and Fire Pokemon for Raichu and Bronzong.
The Toolbox Version will probably see more play because of the type advantage but M Gard will probably still be a decent option
2: M Rayquaza/Bronzong
If you want to play a deck that's has all-around good matchups against pretty much everything in the format M Ray will probably be the best option. It's Powerful, Swift, and Consisntent and can run lots of different things
1: Metal Variants
Why I say this is beyond me, I just think that Metal will be the best because
1. Good Against Toolbox/M Gard
2. Level Ball
and
3. Lots of Attackers (Aigeslash EX, Dialga EX, Heatran, etc.)
Honarable Mentions: MegaMan Variants, Primal Groudon Variants, Primal Kyorge Variants, Night March, Siesmotoad/Crawdaunt,
M Sceptile, Charizard EX, and M Ray/Reshiram