My preferrences. . .

I'm not a theorycrafter, far from it. I play the game primarily for how it makes me feel. The sense of pride after a good instance run, the sense of accomplishment getting a new tier of crafting or leveling to get a specific ability, the determination from trying to get a grasp for a new class (and occasionally the frustration of running back to my body after a 70 decided to gank me for no good reason).

I love character creation in Wow. I love picking out the "look" of my character. I love going through the newbie zones, and then out into the wide world of Azeroth. I love looking at a level one and thinking what they'll be like in 20,30,40,50 levels. I love looking back and thinking how wrong I was.

Having played pretty much every class in the game to a reasonable level (I won't comment on priests because they're the exception), these are the specs I find most fun. Most effective I will save for theorycrafters and people who number crunch, these are the most fun for me.

Paladin - Pre 40 - Ret, Post 40 - Prot - I had to break this down pre-40 and post 40. Pre 40, you just lack most of the abilities that make prot fun. However, I must say there is nothing like the joy of rounding up 3-5 mobs at a time and seeing the damage ticking away on all of them at once. Yes, they might not kill 1 mob very fast, but killing 5 in the same time it takes you to kill 1 makes it very worth it.

Druid - Feral - I love cat form. You're like a rogue, except you are faster, and faster when you stealth. And in exchange for sap and lockpicking (the latter you can get from crafting), you get roots, thorns, and self heals. I never really use bear because if I'm tanking, its warrior or pally. As an off note, since everyone else now gets mounts at 30, does anyone else think the +30% should apply to travel form? Or that travel form should go at least as fast as a normal mount?

Mage - Frost - AOE grinding ftw! I love AOE grinding, ever since I found out about it, I wanted to get good at it. I still need a lot of practice, but it is SOOOO FUN! I don't even care if I get XP for the mobs half the time, its just fun killing 10+ mobs at once.

Warlock - Demonology - I know affliction is the consensus "best" build. I don't see it. Stronger demons take more damage, do more damage, and hold aggro better. Yes, it takes a little longer to kill mobs, I find the extra survivability more than makes up for it. A lot of people end up re-speccing demonology to get the felguard later in the game, I find it fun the whole time.

Hunter - Beastmastery - see above, better pet = better hunter. Marksmanship may be a better pvp build, but I dont really pvp.

Warrior - Fury - I went prot at 60 to run instances. No one seems to want a fury warrior. I wish I hadnt re-specced. I love devestate, but not as much as I love cleave and sweeping strikes at the same time, 4 hits on 2 enemies, yes please!

Rogue - Combat swords - I don't really play a rogue like a rogue, I am too impatient to stealth up to someone, I play them like a dual wielding warrior in leather.

Shaman - Enhancement - see above, except substitute self healing dual wielding warrior in mail.