It's pretty easy to beat a Ray deck in my opinion. Run Field blowers if they use Wishful Baton, and wipe out grubbins or Vikavolts. Also when they have everything set up, once Rayquaza's start getting knocked out, there isn't much they can do.
A really good budget deck is definitely Garchomp/Lucario. If you happen to find it in a regular retail store, pick it up because it comes with cynthia's which are a staple in the current standard format.
During this past weekend was the Madison regional and one deck I was curious about, along with a number of other players, was a notorious Alolan Exeggutor deck. It did very well and was a point short of day two. I am very curious to see what was in this deck so I can possibly create it myself. I...
You can beat Malamar with Garbotoxin or just keep bring out the Malamar from the bench and knock them out one by one. Beast box you could shut down with parallel city since Naganadel relies on the amount of ultra beast on the bench.