I remember the movie King Arthur a few years back. Although the movie for itself was only so-so, I really enjoyed the Mongol/Hunnic stylings of the armor worn.
I've also had a lot of fun mixing styles. One of my favorite lands I'd worked on with my players was the Caliphate of Dikama, a Turko-Japanese land with a Scottish brogue. Samurai with Islamic-Celtic filigree, turbans, and warpaint figured prominently.
So, bring on the historical! All the styles with centuries behind them, they're the true source of awesome. Contemporary styles ('90s piercings and what have you... Love how they're now all dated) should first prove to have staying power. Heck, I'd probably allow for a modern business suit in my fantasy before a modern hairstyle.