This year found the Guild Wars expansion-machine in full swing, with two standalone campaigns released six months apart: Factions and Nightfall. While we were very much into Factions, Nightfall edged it out in our minds. Its North African-inspired setting was extremely cool, and the two new professions introduced -- the vicious Dervish and the stalwart Paragon -- were just too cool for words.
In broader terms, Guild Wars is extremely close to being our favorite MMO ever due to its enlightened approach to the genre. The attention that ArenaNet pays to the game's PvP experience would be embraced by the industry at large in a perfect world, and its ability to offer such a stellar product without charging a monthly subscription is nothing short of revolutionary. If subsequent expansions reflect the level of quality we saw in Factions and Nightfall, then ArenaNet's model will be viable indeed.