One Pokemon?

[Shiny]

Just say you were to only ever catch one proper pokemon and maybe some HM slaves, Which pokemon would do the best at being supper effective at the gym leaders and elite four?

 

[Alter Ego]

Just to clarify: do you want a pokémon that could get the most super effective hits or one that would be best at actually beating the E4? Those are two very different things, you know. Well, it depends heavily on the elites. I do know that in R/S Blaziken could very easily sweep through elites on account of having STAB moves that hurt three of the elites (Sidney, Glacia, and Steven) in all the wrong places while being able to trample the remaining two by sheer force (I had a level 50-something and the only thing that kept it from trampling the whole lot of them was a lack of PP). In FRLG, I'd say Alakazam since the combo of Ice Punch, Thunderpunch, and Psychic gets super effective hits on all pokémon except Lorelei's Jynx and the rival's Alakazam (Well, on the first round that is) and Zam has awesome SAtk and Speed to boot. I'm too lazy to figure out one for the second wave, but basically any high-level sweeper (Heck, just about any high-level pokémon) should be up to the job because the AI is dumb and runs seriously subpar movesets.

 

[Shiny]

One that would be the most effective meaning with attacks.

 

[Synchronize]

Alter Ego pretty much covered everything, regardless of how your latest post still isn't making enough sense to really understand.