One of the coolest aspect of the films for me has been the concept art. It shows a lot of 'what might have been' and-because Star Wars keeps expanding (and of course is revised) beyond the movies, several of the concept work makes it's way into other Star Wars media, as well as reissues of the films.
Here's a link to some of the work from I09:
http://io9.com/5568214/100%2B-amazing-pieces-of-star-wars-concept-art
Some examples/facts:
In the expanded Cloud City landing sequence in ESB's SE, several of the added objects such as the mining platform and the balloon were available only in concept art at that point.
Speaking of Cloud City, it started life as an Imperial prison facility where Leia would have been imprisoned in SW. However as the Death Star concept took shape, the floating city was left for ESB.
There is of course, Coruscant, which was partially based on ROTJ's Imperial home planet, Had Abbadon.
The "Air whales" seen on Kamino in AOTC were originally envisioned for Cloud City, then Tatooine, then Naboo.
The massive "Turbo Tank" seen on Kashykk in ROTS is based on an old Walker concept. Interestingly enough the Tank concept art was already used in the Expanded Universe, so reference books have it as a variant on the concept.
The shot of the diplomatic ship in TPM landing in the Federation hanger bay is straight out of ANH concept art, which had a ship which would eventually become the inspiration for both the Blockade Runner and the Millenium Falcon.
The Coruscant 'bus' seen at the end of ROTJ SE is actually based partially on early concepts for TPM's diplomatic ship as well.
The early RPG sourcebooks and the Zahn trilogy likewise borrowed from some concept art. The Victory-class Star Destroyers were based on concept art of the ANH destroyer; The Rebel gunships on early concept art for the Millenium Falcon/Blockade Runner (Which would also be used for the TPM diplomatic ship).
Finally, the Dathomir witches and Asajj Ventress from Clone Wars were based on Sith concepts for TPM and AOTC.
Here's a link to some of the work from I09:
http://io9.com/5568214/100%2B-amazing-pieces-of-star-wars-concept-art
Some examples/facts:
In the expanded Cloud City landing sequence in ESB's SE, several of the added objects such as the mining platform and the balloon were available only in concept art at that point.
Speaking of Cloud City, it started life as an Imperial prison facility where Leia would have been imprisoned in SW. However as the Death Star concept took shape, the floating city was left for ESB.
There is of course, Coruscant, which was partially based on ROTJ's Imperial home planet, Had Abbadon.
The "Air whales" seen on Kamino in AOTC were originally envisioned for Cloud City, then Tatooine, then Naboo.
The massive "Turbo Tank" seen on Kashykk in ROTS is based on an old Walker concept. Interestingly enough the Tank concept art was already used in the Expanded Universe, so reference books have it as a variant on the concept.
The shot of the diplomatic ship in TPM landing in the Federation hanger bay is straight out of ANH concept art, which had a ship which would eventually become the inspiration for both the Blockade Runner and the Millenium Falcon.
The Coruscant 'bus' seen at the end of ROTJ SE is actually based partially on early concepts for TPM's diplomatic ship as well.
The early RPG sourcebooks and the Zahn trilogy likewise borrowed from some concept art. The Victory-class Star Destroyers were based on concept art of the ANH destroyer; The Rebel gunships on early concept art for the Millenium Falcon/Blockade Runner (Which would also be used for the TPM diplomatic ship).
Finally, the Dathomir witches and Asajj Ventress from Clone Wars were based on Sith concepts for TPM and AOTC.