Can't choose man, I've about 8 fav's:

 

Charizard, Pidgeot, Bayleef, Feraligatr, Ampharos, Noctowl, Blaziken, Sceptile, Buizel

Unlike what the name suggests, lugia. always loved it. Though if i couldnt have it, pichu is obviously the second pick

Probably Metagross

 

I'd love flying above the ground on what pretty much is a psychic flying saucer

Torterra. My favorite

Froakie shiny <3

Either Natu or Zorua, cuz the first one is funny and both are cute :3

Ditto!!! So useful in real life ;)

Well, if we're going down the logical route:

Altaria. It keeps you warm, sings for you, and can take you places! What's not to love, hmm?

 

Buuut.. I'd really like a Primarina. ovo

For cuteness - Mereanie

 

For utility - Mr. Mime (cleaning my appartment is boring)

Alomomola