CT If Darth Vader survived the Battle of Endor...

This would make a good Robot Chicken. AWWWWWK-WARD

<Vader taps fingers together>. Soooo.... Hey....

 

While Luke forgave him, I doubt the Alliance would've agreed, if they don't just instantly throw him in prison it'll be a very long forgiveness process.

 

Even though Luke redeemed Vader and returned him to the light side, Vader/Skywalker spent over 20 years being a member of the Sith religion and in thrall to the most evil man in the universe, commiting all sort of henious atrocities on Palpatine's orders, I think most of the universe would be out for his blood if word got out that he'd survived. Unless Luke hid him away under a new identity, he definitely should and would have stood trial but would probably have been executed / assassinated before it took place.