1.Kirk - soldier, diplomat, tactical genius, could hold his own leading a fleet of ships, or in a bare-knuckle fight; everything a starship captain should be.
2. Picard - the thinking man's captain, perfect man for the time in Federation history that he served in.
3. Sisko - had the best elements of both Kirk and Picard, I only rank him third because I didn't want to have him share second with Picard.
4. Janeway - tough and resourceful, got her ship and crew home against all odds.
5. Archer - I always liked Archer, but he was always at a great disadvantage compared to the other captains, and lacked the seasoning and shared tradition that the others had.
They were all great, each in their own way.