I have, have always had, and always will have a definite weakness for the GTF Valkyrie.
For two reasons:
1) SPEED!!!! All over the place to cause trouble.
2) Has possibly the best word ever as a name.
(Sorry, but I love the word 'Valkyrie.')
That said, I know its missile capacity stinks. Lucky I don't rely on them.
I also like the fact that there's a pair of guns positioned near-as-dammit centrally on the ship's 'chin.' They're shooting right down your axis, which means that if you're aiming in the right direction, they're going to sodding hit!