Armitage, great survivability and lots of firepower.
Kar'fi, lower survivability but massive firepower and tons of tricks. a really fun ship.
Bortesqu' War Cruiser, great fire power and the best survivability of the 3.
Kar'fi is my current fave.
Dr. Patricia Tanis ~ "Bacon is for sycophants and products of incest."
Donate Brains, zombies in Washington DC are starving.
Well, it's a close one for me. Overall would have to say the Rhode Island class. I love the Nova class, and the Rhode Island refit just looks fantastic in my opinion. I love the understated look, and she can be a real thorn in the side of enemy ships with a shield-strip setup. The fleet version flies like a dream too - as agile as some escorts, but able to take a moderate pounding too.
Wells class didn't quite make my personal 'top list' - it's a wonderful ship, but more for it's sense of uniqueness than much else.
As I said though, it was a close one for me - since the Subspace Jump console became available to Fed players I've found myself going back to my Galaxy-X more and more; the Tachyokinetic converter console (from the Lobi store) improved the turn-rate issue fairly significantly - heck, with the aid of the Tachyokinetic converter, Attack Pattern Alpha, Auxiliary to Dampeners and Evasive Manouvers she can turn almost as well as an escort. But the real joy springs from the combo of weaking an enemies aft shields, activating all available buffs to weapons, subspace jump and then unleashing Phaser Lance hell on the unprotected hull of the enemy ship. Fan-tastic!
My favorite has to be the NCC-1701 (no stinkin' A, B, C, D, E, F, J, NX, or other as-of-yet released letter).
However, it's not exactly a viable late-game option here in STO, even with the "movie refit".
Of the "TNG era" ships, the one that I like the looks of the most would be the Nebula, fairly decent looking rebuild of the Miranda.
However, my favorite ship to fly in-game right now is the Tholian Recluse carrier. Yeah, with a science officer in the universal slot it's very light for tactical options, but everything else it has is useful for a decent amount of destruction, especially from a science style vessel.
Yes, I'm going here. Iconic / "hero" ships, I'm talking Galaxy/Defiant/Intrepid here you TNG-era fans, get a T6 version, then ALL the hero ships (Connie, Miranda, NX, etc.) need one too. I'm a ToS fan, and proud of it. This is a themepark, let me enjoy my ride or none of us deserve one...
It's an ugly version of a beautiful ship, it's incredibly difficult to use, and requires the utmost attention to it's build, but the Galaxy-X is a glorious vessel to fly. With the right build it can become a comically maneuverable (for a flying city) death machine.
As for the klingon ships.... I don't really have one, but I enjoy the Kar'Fi. I feel compelled to order chinese takeout from it every time I see one.