In terms of battle, paraflinch Togekiss and choice scarf Garchomp bring so many memories...
Style points go to Absol tho :0
Probably the whole Chandelure line. Don't really have a reason; they just speak to me.
Charizard & Jolteon, Shiny Umbreon a close third.
Blaziken. There is something about a Fire/Fighting chicken that just speaks to me, haha. Also, Sneasel is also up there for me.
eevee is my child
Hell, all of the Eeveelutions, but Jolteon will always be my absolute. Even got plushies of the adorable little guy.
Zorua! Spent so much time getting Shiny Zorua in Omega Ruby! Still have not evolved him and will not ever!