Myself and a colleague have a long term campaign going (nearly 12mths now) and during the game we actually agreed that each race could have one flag-ship type ship, my oppenent built a spreadsheet to calculate cost which seems fairly accurate and I choose to build the Defiant.
Fast, agile, cloaked and tough its 170pts
Shield 40
Damage 25
Then 17 x P3 (split F/PH/SH)
No torps, drones or P1
It get fun to use as I need to get really up close and personal but then packs a real punch and can take a battering!