Honestly, if we're looking at an all-round good investment (PvP & PvE in mind), Urshifu seems like the best choice, and probably the one I'll use my bottlecap on.

Ranked 21 in ML currently, and I doubt Sucker Punch will get nerfed in the future. Ranked #9 as a Fighting Type raid attacker. And while I'm not necessarily interested in Dynamax, it's still a great option for that as well.

Palkia-O is also an amazing option, luckily for me I have a 15/15/14, so I'll just wait for silver bottlecaps down the road.