What exactly do you mean by all around? Do warriors level terribly slow? I really want to be a great raid tank. So Warrior looks the most promising.
All 3 tank classes are viable. All 3 require gear/aa/augs to be viable. Remember a tank will require more time by far to be good enough to tank current mobs, compared to a healer/dps class. That said, a tank is a VERY fun class to play.
Yes go for the warrior if you want to tank in a raid. All though shadowknights and paladins also are tanks, they have other duties on some raids besides tanking. You can read about the warrior here: http://www.thesteelwarrior.org/forum/ they might be better to answer your questions aswell as containing a few guides you might find usefull.
