Tough one.
Succession Wars: I would like something like the Liberator or the Tharkad. They really are do-it-all type ships with ample fighter bays and dropship collars, plus tough armor and enough firepower to hurt just about anything else out there. They both even have NPPC or NL bays that can do a reasonable job at bracket fire. The Tharkad wins on heat management, but the Liberator has that nice armor on the nose and aft. In fact, the only problem with them is their mass. The restriction of a quarter-million tons of ship per year really hurts. That just isn't much tonnage, so we are looking at one of these ships every four years. If it was one every two years, I might still go for them, but only producing three ships in a decade is going to leave me spread pretty thin. This is, honestly, a problem in all of your timeframes.
Being capped at 250k tons per year, I might actually look at the Davion Block II. At 520K tons, I'm pretty sure I could give my workers some overtime pay and squeeze one out every two years. It doesn't quite have the armor of a York, or it's larger fighter compliment, but it is 80K tons lighter, and has much better heat management at the same thrust and dropship capacity.
Clans circa REVIVAL:
Assuming I know, from the dragoons, that I won't be facing any serious warship threat, I'm looking for dropship collars, fighter bays, and cargo space. I want to move large volumes of stuff in an armored shell rather than trying to field something to fight other warships. For that job, you just can't beat the Potemkin. Sure they take something like six years to build one with the restrictions mentioned, but nothing else provides as many collars-per-ton, and the cargo space is competitive with just about anything else as well. For revival, I want an up-armored container ship, and the Potemkin is it!
Dark Age:
Leviathan III. It will take me a decade to build one, but once I do I've got what is, quite possibly, the most broken, OP warship the game has ever seen...in canon. I mean, what are you going to do instead? Build two Mjolnirs or Texas's? I'd gladly take a two-on-one fight with either of those. Three Aegis? Still have you beat on fighters and dropships, and I'll put my armor against three of those. Corvette spam? For the mass of a Lev3, you could build 10 Foxes. That is 120 fighters, 20 small craft, and 50 dropship collars. Pretty impressive, but my one ship has 20 collars, 60 fighters, and 10 small craft, so it's not as big of an advantage as you would like. Plus more armor than all your warships combined and the range, firepower, and cooling capacity to start dropping your Foxes and droppers at long range. Sorry, but nothing is OP like the Leviathan III.
