In fact, as of right now I own 59 81 different variations myself, and there are a couple more hard-to-find variations I know to exist (which I will hopefully add to my collection in the not too distant future)
In recent years, it's been all about Blastoise V, and Blastoise VMAX
Our recommendation: allocate 20 to 30% of your Pokemon portfolio to French editions in PSA 8-9, and keep the rest in English for liquidity
Beyond the obvious advantage its effect grants you, the cards art is pretty aesthetic itself, and the rarity makes it worthy of collecting and keeping in your deck
Finally I will just give some two colour example lists that are fairly stylized
For example, a cards condition and rarity might increase its value, while a decline in popularity could decrease it