[paroxym]

Warrior will be difficult in the short run, but more rewarding in the long run.

Shadowknights and Paladins have more innate snap agro, making them great grouping tanks, whereas Warriors naturally rely more on their proccing weapons and damage, so if you're starting with one as you're first toon with no gear... You'll have a harder time holding hate. You'll still get groups though, low and mid level groups don't tend to be very picky.

That being said when you get into the high levels and especially into raiding, warriors are in much higher demand since they are able to take the hits better with their disciplines and higher defense. If you're planning on doing endgame content, you'll get more out of the warrior in the long run.