View source for Science Fiction-Genre

What follows are some things I think would work together to make a good science fiction setting.  Some of them are general and would work in other genres as well, I think they are especially important here.  I will also give some examples of film and literature which utilize these tropes.

=Feudalism=
Having a hierarchical society with stratified leadership and all sorts of high falutin titles is interesting and fun.  I dont know why this is so much more alluring in this setting than it is in [[Fantasy-Genre]].  I like it there as well, but in Sci-Fi somehow its absolutely necessary.  Maybe its because it allows an extra level of court intrigue, or because its the kind of alien government we can all understand.

==Examples==
One example of a setting that utilizes this trope is Dune.  Count Hasimir Fenring is known as the deadliest man in the universe with a knife.  That would not sound quite so cool if it were Vice President Hasimir Fenring.  Even colonel Fenring doesnt quite sound as good. 
=Diversity=
Lots of different cultures and races each with their own defining qualities are what make space adventures go.  Not only is this the wonder of exploration, but it is also an excellent opportunity to experience culture shock.  These far reaching differences are essential to the scope of the setting.

==Examples==
Star Wars and Star Trek both do an excellent job of introducing many kinds of races, bipedal and otherwise.

=Interesting Technology=
Nothing is off limits.  Wanna travel light years?  How about extend life 10,000 years?  Anything is possible.  Wonder...thats what Sci-Fi is all about.