Least amount of Utility, end game DD: Monk. Its a "Set it and forget it" job. Fun in it's simplicity. And particularly easy to gear up on the AH or by questing. If you want to be top tier, you'll have to invest a considerable time in an end game LS just to aquire the Monk's "Crown jewels" B.Haidate, Blackbelt, etc. But even a relatively "Decently" geared Monk will do "Above average".
War comes in a close second, it's SMASH SMASH SMASH, but requires a little more care, you need some hard to attain gear to reach the upper tiers of efficiency, but it's versatility aids in it's usefulness. You can Great Axe just as well as you can dual wield. All and all as far as efficent damage in most situations War would probably be king, if anything based solely on the ability to tank when needed.
Sam is nice, and got to say a VERY forgiving job. I notice an exceptional amount of Gimp Samurai running around that amazingly still get picked up for parties and such. The job is confusing. I say that only because of the gear choices and actions I see in the field. If you have half a brain you can make that job work. If you had a complete brain, you can make that job shine. Versatile sub choices lend it to be more of a pain to coordinate in situations. People expect certain things of you that are contradictory to the goals of the job. For instance, people will ask you to merit as /ninja, while this seems liek the right thing to do, it's like asking a police officer to give up his gun for an armored car... With the removal of the main cause for being an MP sponge so goes the need for subbing nin... But I aggree that /war is like giving the same police officer a gattling-gun... There's multiple other subs that are very good for very different reasons and situations. Which in short makes the job a little more complicated.
Ninja is an interesting choice. Sure you can be a bad ninja, but you'll likely still get invites. Its one of the few jobs that can safely hide under the asumption "Even a bad XXXX is better than no XXXX."
Dark Knight: Imagine the Samurai's above police analogy. Now instead of giving that police officer a gattling-gun you were to hand them a couple nuclear warheads. Not only to you not solve crime, butyou piss off everyone around you too. Darks can be played well, but the people that play the job typically dont' care about the rest of the party enough to play safe. And while your group is waitign for the Drk's weakness to wear, he/she will be ranting about how glorious thier death was.
I think a different angle on this question would be: Which of the DD jobs would give me the least amount of headache.
Mnk: Merit invites(as to be differentiated from EXP parties), used in Salvage, other than that, good luck, you'll be last in line for most gear because its all used by other more "Useful" jobs, and the game dynamic doesnt' lend itself to DoT jobs, due to the mob TP system.
War: Easy and versatile, first pick in merit parties, decent invites in EXP parties, mildly useful in endgame situations, and easy to gear on the AH pretty much from the start, to the end. And you can reach a higher tier through end game on about 6 different fronts: Sky, Einherjar, Salvage, Hunting, Land Gods, Nyzule Isle. All of which you are a very decent to good addition to.
Sam: Pretty much said everything I needed to above. It's a very good job for big fights.
Ninja: There's 1 good ninja on our server to every 1,000 bad ninjas. and those 999 ninja will be quick to blame everyone in the group before taking the blame. They get first pick on a lot of gear, and most people level it just to get gear for another job... Which is a dominant cause for the watering down of the pool. This is a super fun job, and I reccomend it, if you're really going to be serious about it.
Dark Knight: Kinda hard to get parties, gear is simple and available, Dark gets one thing no other jobs gets in that arena: Little to No competition for gear (Exception being E.Body). It's a tremendously fun job and actually lends itself to a decent level of "soloability". So you can go and do stuff while you wait on party invites... Which you will wait for...
