>>47164275Onix and Nosepass are near the top of the list. The pokemon are borderline unusable in the player's team, or at least as close to that as can be achieved in a pokemon game, while being pretty imposing on the first gym leader, by sheer dint of not having the tools to get around them.
Milotic and Spiritomb; the requirements to get one are beyond asinine, they are clearly meant to be boss pokemon you can't get.
Odd case, gen 4 Snorlax. Munchlax has similarly asinine catch requirements, and it is pretty clearly just meant to be Barry's anchor.
Kind of an odd group, the Kanto Underrated Shitmon Gang, largely consisting of Zubat, Tentacool, Geodude, Magnemite, Machop, Doduo, Oddish/Belsprout, and probably one or two others. These pokemon were filler and mostly just a nuisance in gen 1, but have gone on to be some of the most reliable, yet consistently shit-talked pokemon in the series in later gens.
Everyone sighs and groans when you encounter a Zubat or a Tentacool, but legit, they are consistently in the top 10% of ingame regional dexes.
Unironically, pseudos before gen 6. Getting a pseudo almost always entailed some obscure location you backtrack to, with an underlevelled shitmon that you dump obscene amounts of resources into, that you may not even be able to reasonably obtain by the end of the game, purely intended to give the last few trainers some sort of ultimate boss pokemon that could actually threaten the box legendary.
And then Tyranitar, for some fucking reason.
Tough group to categorize, but the "unusable early learnset" crew. Grimer is the posterchild for this, but Zubat(again), Ekans, Seedot, Lotad, Duskull, and so on. Pokemon that simply do not work if you get one early, by dint of having like, 15 BP, non-stab or off-attack stat moves at their disposal.
Ralts. Ralt's is Wally's exclusive pokemon, the line itself mostly is engineered to mirror Wally's own development, and Ralts itself, as well as Kirlia are virtually unusable.