@ Luke

Interesting question!

I am ally all the way. I did play Horde a bit in TBC, but found maintaining 2 sides to be too difficult. One of the major reasons I prefer alliance over horde is the HOLIDAYS! Holidays are so much better on alliance. Every single holiday just fits - Brewfest most of all! Also, I love all of the alliance cities - the grandeur of Stormwind, the pensiveness of Darnassus, the sci-fi vibe of the Exodar, and the depth of Ironforge!

The Horde races I love are the belfs and tauren. I like their cities as well. The music in Silvermoon is great and I don't think anyone would say that the city isn't absolutely gorgeous. It has such a grand old magical feel to it. I also enjoyed playing a blood elf - they have such a great lore edge, and it was especially prevalent when I played in TBC. As for the tauren they are just so calm and peaceful. Playing them and hanging out in Thunder Bluff are great ways to just unwind and enjoy Azeroth at the end of the day.

However, I absolutely hate the Forsaken. I got my belf up to like 63 when the cap was 70 and started grinding their rep to get the purple skelly pony and everything was BLAH KILL ALL HUMANS and BLAH POISON THIS SWEET PUPPY (poor 'lil stanley....)
As for the others, I don't necessarily have a problem with them, I'm just not interested in playing them.

I have played Alliance for so many years though now and when I think about playing Horde seriously it does bother me. I wouldn't feel bad about popping over and playing on a lowbie, but pushing to 85 and gearing up just wouldn't feel right to me - especially since I love to BG so much.

I'll stick to wandering enchanted forests and contemplating mortality with my nelfs :)