Yeah, DPP UU was the shit. Its main Pokemon definitely had a solid grip on the tier, but it was loose enough that you could bring some Pokemon from the depths of NU (Mantine, Magcargo, etc.) and they'd do great. You could make a hyper offense team and a stall team, and if you were a decent player of both they'd see similar winrates, because for the most part all strategies were viable in DPP UU. Out of all of the singles metagames I've played, it's the closest thing to a "perfect" metagame that I've ever played.
There are also several side metagames that are pretty darn fun, like Balanced Hackmons and the OffStat metagame, but I'm assuming this thread is for official metagames.