Warrior vs Revenant
Warrior is the better of the two. Revenant lacks flexibility (your 6-10 skills come in a set, no way to mix and match). Warrior is pretty much always welcome given its superior might stacking capabilities (look up Phalanx Strength builds). Solid power and condi builds, good sustain, static boosts to groups stats with banners, etc etc etc.
Revenant was a good idea, but…. Shrug
Edit: I leveled a revenant to 80 and consider every minute I spent doing that time I’ll never get back. Warrior is pretty easy to use (imo). Always welcome in group content. Can’t speak to WvW. I have enjoyed Warrior greatly, and with its wide array of weapons, you can switch around and keep from getting bored. Works well at melee and range. Berserker is great for condi builds, but is still a damage booster for power builds. (Herald does do boon support well, but there are other and usually better ways to get those boons.) Thief… isn’t as good as warrior, and aside from Basilisk Venom, doesn’t have much to contribute to group content aside from raw damage, which can be gained from other classes that also benefit the group in other ways. You will learn active defenses with a thief, or die trying. Something to always work on regardless of class. Staff is an awesome weapon (gained with Daredevil, which focuses on Staff and dodge/evades.)
(edited by bearshaman.3421)
Thief is a pretty quick leveling job due to how much quickness and movement they can use.
I’m going to assume the you (OP) are fairly new to the game. With that in mind, I recommend Warrior. I love Revenants, and I main a Rev. But getting a Rev to 80 and completing its Elite Spec is quite an unpleasant grind compared to the Warrior. Also, the Warrior has the highest potential health pool in the game, making it a lot more forgiving of mistakes than the Rev. And while the thief is great fun, it is a very fragile character compared to War or Rev.
All that being said, I would definitely recommend playing a Rev and a Thief at some point. Both classes are a LOT of fun once you understand and master the basic game mechanics. And the most important thing about GW2 (or any game) is that you have fun playing it!