Master of Orion II: Battle at Antares/Ship Leaders

The lists of Colony and Ship Leaders is in alphabetical order and the following format:
 * Picture and name of the Leader.
 * The Leader's statistics. These normally include (where known):
 * Costs.
 * Starting experience. New levels are attained at 60, 150, 300, 450 and 1000 experience points.
 * For each skill, how powerful that skill is and how much it improves per additional experience level. Skills marked with an asterisk will increase more per level than skills that are not.
 * Our comments and recommendations.

Ship leaders will in most games make less of a difference than colony leaders, but it depends on how you build.

Remember that abilities such as Assassin, Diplomat, Famous, Megawealth, Operations, Researcher, Spy Master and Trader works even from the officer pool, as does the map view benefit from Galactic Lore, so if you are happy just using those abilities, just recruit and forget.

Also, don't bother placing leaders on smaller ships (the only exception would be an escort ship with a Navigator leader, that retreats at first sign of trouble), and be aware that in multi-player games having a ship with a leader on it will almost certainly make the opponent prioritize that ship.

All that said, a Titan or Doom Star can benefit enormously from a good leader.