depends on my mood, really. I plan on getting all three johto starters by trading back and forth with diamond, and get the sinnoh starters at the start as well, so I'll have a team of starters. Basically I'll have whatever starter I'm using at the time follow me.
Oh, and once I get enough badges, I'm sending all my pokemon from diamond over, and then my dark types, absol, umbreon and mighthyena will switch out with following me around. And yeah, darkrai. enough said.