>>28165177Shiny figures happen only very rarely, and only for iconic stuff like red gyarados. Same with plush, although I've seen a few more of those.
I know for a fact that the Tomy Electrode is the rarest from Gen 1 - I'll certainly be getting a dupe because real ones go for about $250. I would say that's the rarest one of all because of course the more recent figures are less valuable. The main Tomy Ditto is also crazy rare (I ordered a slightly silly-looking Ditto that was made later and is in a more active pose)