I initially rolled alliance due to my parents and the rest of my family's wishes to play alliance, I did not want to play anymore MMO's at the time...but having the medium available to keep in touch with them and have some fun activity while I was hours away in a hotel room made playing WoW a logical choice. This was at release.
About a year later we decided to reroll horde, and thus Skathac the Orc Warrior was born in the World of Warcraft. Had alot of fun with him, much insanity followed. Had just as many alliance friends as I did horde during my heyday on Twisted Nether, this was before the first expansion. Eventually drama killed the game for the family and I.