I've always been a massive sucker for
Warhammer 40000's Corvus armour. The armour's as awesome as ever, but it's
that damn beakie helmet!
I've also always loved the Jedi General armour from
Star Wars ever first seeing Obi-Wan wear it in the first Clone Wars miniseries, and I particularly like the version of it that appears in
The Old Republic. It's that combination of the plate armour and cloak I think that makes it so badass - it has both that mystic monk element of the Jedi robe and the warrior element of the armour.
Finally, I do rather love the bonus armours you can get in the
Assassin's Creed games, specifically the ones in the Ezio trilogy. I know they're mostly just intricately designed robes with some bits of armour stuck over it, but even so, they're impossibly cool. My favourite has to be the Armour of Brutus from
Brotherhood - it has that badass Roman centurion style going on, plus the intricate chestplate all combined with the awesomeness of the regular assassin robes.
Speaking of
Assassin's Creed, I can't believe this armour was cut out of
III. It's just the most kickass thing.