Ho-Oh
Lugia
Celebi
... Pichu (i don't feel very confident about it, without smash ultimate i'd say he's not there now, but since he is...)
i think suicune is damn close but not close enough (
being competitive meta in gen 2/3 is good and being box legendary of crystal is significant too, but not as much as ho-oh and lugia's bigger box legendary statuses (and anime/movie roles) and celebi's movie boost (plus being equally competitive-relevant)
), and esp/umb (
obv reasons, being the most popular eeveelutions besides maybe sylveon or vaporeon, they even have strong presence in spinoffs
) are in contention for sure too.
also raikou and entei are somewhere around top 10 at least (
boosted by ova and movie relevance compared to sui
) along with ttar (
thanks to long standing competitive relevance and also presence in stuff like unite
) and wobbuffet (
90% thanks to the recognisability from the anime after all this time
). marill and togepi
might
also be around there too but i def don't think they have enough factors to push them any higher than that really