First off let me say this thread will probably be closed for the fact that this has been done a hundred times.

However, on that note...

Cloud- Hayden Christiansen
Barett- Anthony Anderson
Tifa- Jenna Jameson
Aeris- Anna Paquin
Cid: Chuckie Norris
Sephiroth- Marilyn Manson
Yuffie: Emma Watson

And staring:
Palmer: Dr. Phil