
My first exposure to Pokemon was the Nintendo Power article where they first talked about Pocket Monsters, I got Pokemon Red in 1999 for my 21st birthday. But I also had a young nephew with whom I'd watch the Pokemon cartoon, and i got him and myself one of the gold-plated Pokemon cards from Burger King.
Of the Pokemon spinoffs, Pokemon Stadium on N64 looked most interesting, mostly because i thought it was going to be a full on RPG and I wished to God that Nintendo would make a couple of N64 RPGs, that being back when I still held out hope for Earthbound 64.I could see the appeal of having your Pokemon live on TV in 3-D. A lot of the battle animations were actually more detailed than in Sword/Shield. That said, didn't invest in Stadium. I never played Colosseum, either, but I was kind of interested because the region it's set in is based on Phoenix.
Other than Pokken, I never got into the other spinoffs.