They may be uber famous now and able to get any role they desire,  but at one point, celebrities had to read for roles just like everyone else.  Watching the audition tape of an actor or actress is usually fun, as you get to see their take on the character before it’s polished and fully realized.  I found eight great celebrity audition tapes, and you can view them all after the jump:

Natalie Portman – The Professional

httpv://www.youtube.com/watch?v=CqNfJCJUD08

Natalie is a smokeshow now, and she’s just adorable in this audition tape.  I’ve always thought she was a talented actress, and it’s hard to imagine The Professional with someone else in her role.

Seth Rogen – Freaks and Geeks

httpv://www.youtube.com/watch?v=Gyl8ILulOD4

The link between Seth Rogen and Judd Apatow goes back further than The 40 Year Old Virgin.  Here you can see a younger, slimmer Seth auditioning for the cult show Freaks and Geeks.

Michael Cera – Superbad

httpv://www.youtube.com/watch?v=Y9YsztY65V4

Funny, you can hear Seth Rogen reading for the role of, um, Seth, that was eventually filled by Jonah Hill.  Cera has the awkward geek role nailed down perfectly.

Carrie Fisher – Star Wars

httpv://www.youtube.com/watch?v=kCXrGuLix7M

Like Portman in The Professional, it’s very difficult to imagine someone else playing Princess Leia.

Kurt Russell – Star Wars

httpv://www.youtube.com/watch?v=nix_PID3oiA

Russell auditioned for the role of Han Solo, but the role obviously went to Harrison Ford.  Ford was perfect, but I think Russell would have been real good, too.  He’s great at playing the rugged bad boy with a heart of gold.

Russell Brand – Forgetting Sarah Marshall

httpv://www.youtube.com/watch?v=DoQrPsuSlWU

One of my favorite comedies of last year, and it wouldn’t have been the same with any actor besides Russell Brand.  I feel like the role of a rock star can be taken in a lot of different directions, but apparently people liked what they saw in Brand.

Matthew Fox – Lost

httpv://www.youtube.com/watch?v=sXrtvwqseu8

Here is Matthew Fox reading for the role of Sawyer, and if you watch Lost, it’s got to be a bit trippy watching Matthew Fox as anyone other than Jack Shepard.  Would he have made a good Sawyer?  I think so, but it’s still weird to think of him as anyone other than Jack.

Megan Fox – Transformers

httpv://www.youtube.com/watch?v=nvj1grWPnDg

Her acting skills aren’t great on this tape, but I have a strong suspicion that wasn’t what landed her the role in Transformers.