Hey guys, Nick "Berserk" Walterhouse here—wait, what? Not my line to say? Well then.... This post is more for myself than anything but I figured that if I was going to compile this information that I might as well share it with the community, even though the data that goes into it is pretty volatile. I am probably going to end up updating this list weekly as long as I have enough time but if anyone is interested, the order of Pokemon in this list goes Mega ➡ Weather Trio ➡ "Uber"/Formerly Banned Legendaries ➡ Other Legendaries ➡ Non-mega/Legendaries. I included the names of every Pokemon to make it easier to find all of the teams with a specific Pokemon on them. I will also add in usage stats and thoughts on the format sometime tomorrow.
***Disclaimer: This list is never going to be "current" just because of how often showdown rankings update, but it should provide a good baseline for what is popular in the meta at the moment 

       

2. Daflo: Xerneas/Yveltal/Kangaskhan/Salamence/Crobat/Landorus-I

      

3. DesuzakiddoVGC: Kangaskhan/Groudon/Xerneas/Cresselia/Hitmontop/Talonflame

 

4. Isaby: Kangaskhan/Groudon/Xerneas/Talonflame/Smeargle/Ditto

          

5. Silk: Rayqyaza/ Ho-oh/Landorus-T/Ludicolo/Aegislash/Ditto

   

                  

6. Stadtfeld: Groudon/Xerneas/Kangaskhan/Salamence/Amoonguss/Liepard

         

            

7. Kumanano: Salamence/Groudon/Xerneas/Cresselia/Amoonguss/Liepard

  

           

8. Clale: Kangaskhan/Salamence/Groudon/Xerneas/Amoonguss/Liepard

           

9. Tapidayo 

    

    

10. Linlinlink: Salamence/Kyogre/Xerneas/Amoonguss/Liepard/Crobat

                  

11. Soranerikuno: Rayquaza/Groudon/Cresselia/Liepard/Crobat/Weavile

             

12. Vermouth: Salamence/Gengar/Groudon/Xerneas/Amoonguss/Liepard

   

              

13. KRSW2783: Mawile/Kyogre/Yveltal/Cresselia/Landorus-I/Ferrothorn

     

           

14. Kujyou_miyuki: Salamence/Groudon/Xerneas/Amoonguss/Liepard/Togekiss

                       

15. Featherya: Kangaskhan/Groudon/Xerneas/Clefairy/Smeargle/Talonflame

              

16. 7 POISONOUS SINS: Kangaskhan/Groudon/Xerneas/Talonflame/Jumpluff/Mienshao

   

17. Tapinano

      

      

18. Menci: Kangaskhan/Groudon/Xerneas/Cresselia/Landorus-T/Aegislash

         

19. Lithiumacid: Kangaskhan/Groudon/Xerneas/Talonflame/Togekiss/Gengar

  

20. Moudamedayo

        

      

21. Fyaid

      

      

22. Pokelop: Kangaskhan/Groudon/Xerneas/Landorus-T/Smeargle/Amoonguss

             

23. ysdpoke: Kangaskhan/Groudon/Xerneas/Smeargle/Crobat/Whimsicott

24. Static Sound: Kangaskhan/Groudon/Xerneas/Talonflame/Scizor/Smeargle

            

25. GeporA: Kangaskhan/Salamence/Groudon/Xerneas/Cresselia/Aegislash

26. welby_night: Kangaskhan/Salamence/Groudon/Xerneas/Thundurus-I/Amoonguss

       

27. snecarp22 test: Mawile/Kyogre/Dialga/Cresselia/Thundurus-T/Ludicolo

        

28. troopdawg: Kangaskhan/Kyogre/Xerneas/Ludicolo/Aegislash/ Gothitelle

              

29. pyromaniac720

      

      

30. Scrub Lord Jim: Mawile/ Groudon/Xerneas/Amoonguss/Crobat/Liepard

   

   

31. stantlerbestmon: Kangaskhan/Groudon/Xerneas/Landorus-T/Smeargle/Clefairy

          

32. Burning Seas: Kangaskhan/Groudon/Yveltal/Cresselia/Thundurus-I/Aegislash

               

33. 16nightsakuya: Rayquaza/Kyogre/Crobat/Togekiss/Weavile/Aegislash

            

34. Ed29: Lopunny/Groudon/Xerneas/Thundurus-I/Crobat/Aegislash

               

35. shada1999: Kangaskhan/Rayquaza/Kyogre/Latios/Heatran/Excadrill

   

36. Racs: Kangaskhan/Salamence/Groudon/Xerneas/Thundurus-I/Amoonguss

   

37. aprina

      

      

38. Sayha: Kangaskhan/Groudon/Xerneas/Talonflame/Smeargle/Clefairy

     

39. uaaa: Kangaskhan Groudon/Xerneas/Heatran/Gothitelle/Whimsicott

      

40. Raisethedonger

      

      

41. spookydragon: Kangaskhan/Mawile/Kyogre/Giratina-O/Cresselia/Landorus-T

42. Lore95VGC: Kangaskhan/Groudon/Xerneas/Talonflame/Whimsicott/Amoonguss

   

43. miwanissimo: Salamence/Mawile/Groudon/Kyogre/Cresselia/Amoonguss

    

44. TM_Silv3r: Kangaskhan/Groudon/Xerneas/Thundurus-I/Amoonguss/GOLDUCK

        

45. JohnSun: Kangaskhan/Rayquaza/Kyogre/Cresselia/Talonflame/Amoonguss

   

46. Kanchan

      

      

47. snow-pokepoke: Kangaskhan/Gengar/Groudon/Xerneas/Thundurus-I/Whisicott

   

48. MagicalWizard111: Kangaskhan/Mawile/Kyogre/Mewtwo/Landorus-I/Talonflame

49. rarishula: Kangaskhan/Kyogre/Xerneas/Cresselia/Landorus/Amoonguss

           

50. VaPzitar: Salamence/Mawile/Kyogre/Xerneas/Cresselia/Liepard