>>53974379People get up its arse a lot, but honestly? Uranium. Actually good story that uses the nuclear type gimmick well, and whilst the quality of the fakemons is inconsistent, there are plenty enough bangers to build a team out of. I also like how most are double-typed (making them quad-weak to nuclear), subtly reinforcing the idea of how frightfully vulnerable Tandor was to a nuclear disaster through gameplay.
I also, though it's not really old enough to have aged like anything, heartily recommend Realidea System. If you can look past the dodgy, incomplete translation, you find a game with good QoL features, beautiful tilesets, decent animated sprites for gen 6 and 7 'mons, and a surprisingly character-driven story. Unlike Uranium, only the starters are fakemon, but all three are pretty good.