In no particular order:

[color=#FFFF99]Freespace 2's Shivan Mara

[color=#99FFFF]A heavy space-superiority fighter that not only was ridiculously awesome to fly in the one mission you had it in, but also looks like a spider in a way.

Freespace 1 and 2's Hercules

[color=#99FFFF]A heavy, beefy thing that was tough to crack and carried one helluva lot of firepower.
Plus you could fly it really, really often actually in Freespace 2.
Aaand it also just has this rough, sturdy look to it.

StarCraft's Terran Wraith

[color=#99FFFF]I just always liked the design of the thing.
Stood out from everything else for me.
Still does, really.

StarCraft's Terran Battlecruiser

[color=#99FFFF]Not much to say, love the design again.
It just looks strong and mean with the hammerhead-esque front.
And it has the Camato Yannon. <3

EVE Online's Machariel Battleship

[color=#99FFFF]In a sense 'cause of the design but it's more the fact that among all other Battleships in EVE, this one stood out the most for many reasons.
Plus back when I played the game, the thing was just so ridiculously awesome.

X-Tended's Terran Thor Mk.II

[color=#99FFFF]Everyone who flew this thing knows how great it was in the game.
Heaviest shielding a fighter could get, enormous powercore, eight gunslots and a quad turret to cover the rear.
Simply awesome.

Wing Commander 4's Banshee



[color=#99FFFF]One word: Looks.
(It also came with a shotgun. Seriously.)

The Viper Mk.II

[color=#99FFFF]Nothing to say here but this: <3