I know I'm the only one who has said this so far, but I love my warrior. I feel so powerful. Not sure if it is the best class, but for me, it is defiantly the coolest!
This is not a question to be asked, but a question you have to answer.
What I mean is, no one class is 'the fun class.' They are all fun, to someone.
I can play a druid heals better than a priest, pally or a shaman healer (and yes I have one of each), but thats me and my play style, not everyones.
The best way to get your own answer (as it should be done) is to play a class to level 10 and read a bit on the class. If by level 10 you arent enjoying it, dump it.
There are other factors to consider for a class other than the class itself, I have found. For instance, at the beginning of playing I didnt care for rogues or gnomes. One day I made a gnome rogue and have leveled him to 56 now just doing BG's, mostly off "Call to Arms." There are many factors to getting a toon you love than just shaman or rogue or lock or <enter class here>.
Keep plugging away and you'll find the right combo to get you excited about playing.
I agree with Lokilo, but i think you got something wrong.
Lvl 10 says NOTHING about endgame play with a class!
I would rather say that you should take a good look at the class before you start lvl'ing it, maybe go read on the forums or just join a dungeon and check out the other classes!
You can't judge a class on the first 10 levels, please don't do that!
I agree play at least to level 20 do some dungeons, BGs and dueling to see if you like the class. I play priest for the shield, rogue for stealth, and hunters because of pets simply because I suck at PvP.
My personal opinion, the coolest and most awesome class is a Druid
Because you get to experience almost everything the game have to offer with 1 class..
1. You can be a healer
2. You can be a melee DPS that kinda like half Warrior (Bear) half Rogue (Cat)
3. You can be a caster DPS with good CC like Mage and Warlock.
4. You can be a Tank
Druids are versatile and awesome. I play a Paladin for the same reason but, they lack a ranged DPS option.
I would always suggest a hybrid-class to newcomers, only because of the fact that they can try to dps/heal/tank on the same char!
Chances are few that you will try both tank, healer, boomking and cat as druid, so playing Pala will work perfectly too (they lack the ranged dps, but still have tanking, healing and dps). Tanking is maybe not the best role to start with, so starting a shaman (who can be healer, meele and caster) is not a bad idea either.
I like lots of classes and each has a different sense of coolness. An Enhancement Shammy can pull so much out of the bag. Frost DK are awesome in a big fight and how can you not love the Druid flight form, but I have to say for me when i am on form with my Combat Rogue I love it the most. True it does die easy against some of the big bosses, it needs a good tank to hold the aggro and benefits most from all the other classes buffs, but when all you want is to take down a boss, it can really rack up DPS.
My Frost DK is the one I have to go with at the moment, only because I love wrecking bosses with high crits and high mobility (Unholy Pressence), but back in Wrath Blood where much better, oh Blood, where did you go