Fighter: Thunder: They aren't as good as they used to be (easier to kill with a two-man wing), but their speed is ridiculous, and they are the best tacklers out of all the fighters.
Frigate: Tempest, as I run for Hi-Tech Fleets. Phase Beam and Pulse Laser are my new-found companions on this ship, as I tend to to go after Low-Tech and Hegemony instead of other Hi-Tech fleets (you have to swap out the phase for something good against shields against Tri-Tach sadly). Its just so fast, and with a phase beam it can literally just sit on a ships engines and keep them disabled.
Destroyer: I don't really use destroyers, actually. But I'd have to go with the Eagle since I found out about the Mauler-HAC-Mauler combo in the front. It makes for a fantastic support destroyer (and with the new Maneuvering Jets, she's fast too!)
Cruiser: Apogee for life. She's my Flagship. Plasma Cannon, Two LRPD, Two Phase Beams, Hardened Shields - she can stand up against capital ships and fleets and shrug off thousands of damage, 'specially with Elite crew. Just so hard to kill, though a little slow.
Capital: Odyssey's are my favourite capital. One Broadside is not bad with its good shields, a flight deck so you don't need a dedicated carrier, and with Plasma Cannons its System does ridiculous amount of damage from good range.