In the EU I think that Stackpole and Aalston both did a great job of creating characters who broke from the norms. Stackpole created Asyr and one of the first inter-species relationships between Gavin and Asyr. Aalston made Piggy, our stereotypical non-stereotypical fellow, I suppose, and tacked on Runt, creating a whole new species for the EU. We also have our first de facto racists in the form of Castin (I always hated Castin...). The Twi'lecks were also developed rather heavily; Tal'dirra, Nawara Ven, Dia Passik (sp?) all had distinct, very differant personalities. The Mon Calamari aren't looking so hot now, either, with Niathal in the Legacy of the Force books (Don't post any spoilers- you can only know that Niathal is not a good Mon Cal). There were others, too, I'm sure, but I don't know them very well off the top of my head.