first gen
>strongest stab is Lick
>weak to Psychic, the best type in the meta
but then
>fastest sleep user with Hypnosis
>fast Explosion user, doesn't get hurt by other 'sploders
>nothing amazing but given Gen I's standards, being decent was all you needed
second gen
>new weakness in Dark, Pursuit is also a thing
>Shadow Ball and Sludge Bomb new stab moves, but both types are physical so they're shit
>Hidden Power means every type can hit you supereffectively if they so wish
but then
>elemental punches as TMs make great coverage
>immune to Rapid Spin
>gets neat moves like Perish Song and Destiny Bond, allowing it to beat foes without force
third gen
>Levitate removing its Ground weakness
>Will-o-Wisp and Taunt to mess opponents up
>can even run crazy sets like Substitute Focus Punch
>I didn't forget the disadvantage section cause THERE AIN'T ONE
fourth gen
>STABs now available as special attacks
>Focus Blast provides perfect coverage
>I guess a physical Pursuit and Sucker Punch ruins its day but who cares when it still outruns the users of the former and can Sub on the latter
>in case you missed it SPECIAL STAB MOVES
fifth gen
>see above
sixth gen
>steel lost their ghost resistance
>the new type, fairies, are weak to its other STAB
>why the fuck aren't you using Gengar
>pretty much no one objected to banning its mega because why would you want to be alone with that thing
seventh gen
>Levitate replaced with Cursed Body, and thus its Ground weakness is back on the table
>feelsbad.jpg
but then
>being grounded, it can now absorb Toxic Spikes
>can also now exploit terrains since you need to be grounded to benefit from them
>plenty of new fairies to threaten with Sludge Bomb
>Z moves is straight up its alley to lure or just plainly crush foes with
I am unsure if I'll ever live to see the day when Gengar isn't good. Seriously, it was OU for three gens straight without using STAB moves, I can't emphasize that enough