With the news of an Danny Phantom live-action movie project. I tought of a wishlist of actors who could play the following roles. Note then it's more of a pipe-dream fantasy then a real list.

Danny Fenton/Phantom: Justin Long, he played a unlucky high school student in "Dodgeball" and I think he might fit the role more then Drake Bell.

Sam Manson: I go a bit outside of the box for this one: Cherie van der Merwe, an actress from South Africa who starred in the movie Bakgat. [link]

Tucker: One Youtube user mentionned Tyler J. Williams [link]  and I gree with the user's choice.

Jack Fenton: I got 2 choices; 1st Kevin James or the 2nd choice, French-Canadian actor Remy Girard.

Maddie Fenton: Christine Taylor

Jazz Fenton: Julie Gonzalo

Danielle: Missy Peregrym, a Canadian actress [link]

Dash Baxter: Trever O'Brien

Kwam: Doua Moua [link]

Mr. Lancer: Marius Weyers [link]

Valerie Grey: Kyla Pratt

Mr. Grey: Ernie Hudson

Paulina: Camila Banus [link]

Vlad Masters: Alec Baldwin

Dark Danny: Matt Damon

Edit: I forgotted to mention Sam's parents: Jeremy and Pamela

Jeremy Manson: 1st choice Kevin Sorbo, 2nd choice Matthew McConaughey

Pamela Manson: Kate Bekinsale

Grandma Manson: Sandra Prinsloo  [link]