Here's the list so far, let me know if there's anyone missing:

Luke Skywalker: Mirai Trunks [DBZ]
Darth Vader: Belldandy [OMG]
Han Solo: Chad [SM]
Princess Leia: Akari Unryuu [R1/2]
R2-D2: Makona [MKR]
3C-P0: Kamidake [TM]
Obi Wan Kanobi: Kuwabara Kazuma [YYH]
Ewoks: Fushugi Yuugi cast
Sand People: Maison Ikkoku cast
Emperor Palpentine: Ikari Shinji [EVA]
Boba Fett: Leona Yamazaki [Dominion Tank Police]
Chewbacca: Tina Corman [Teknoman]
Yoda: Nuku Nuku [APCCG: NN]

Did I forget anyone?

TekkaKnight WarHammer