Best of type?

This site is awesome - just click on "Moves List" from the menu -
https://pokemongo.gamepress.gg/pokemon-moves

Select the type of moves you want to research

Click on the desired move - shows PKM who know that move in descending order by ATT base stat!

Peep this site. It's in French but mad in-depth.

While not being completely practical, they took each Pokemon + moveset and tested vs. every other one in the game running thousands of simulations. All have been ranked.

Unfortunately that sometimes does more harm than good b/c if an attacker can beat up on stupid mons nobody uses on Defense it will be ranked too highly vs. other Pokemon. For example, Flareon top 10 is ridiculous. Once you click on who it's best vs. you see a "who's who" of Pokemon you're never going to see on defense anyway. Parasect, Unown, Farfetch'd, Yanma, etc.

However, for comparing two mons of the same type it's great b/c it's a much more relevant comparison. So if you were to go through and just look at where each Fire Pokemon ranked it would give you a much better idea of which was the strongest combination of stats/movesets.

http://goptimiz.fr/attaquants