I think the two most prevalent cases are tanks and dps. In general, dps accepts damage meters such as recount, are the end all of who’s doing the best, but tanks are a little harder to sort out. This leads to tanks boasting about gear, stats, avoidances, and all other things they might be able to bring to the table.

In a world that is as unquantified as tanking, its often very difficult to match up exact tanks against other tanks, especially when the 3 (soon to be 4) classes have varying degrees of differences. Additionally, most of the fights that blizzard designs, have 1 target to tank, and if there are more, they are often clearly designated as “off tank” style mobs. Trash usually requires more than one tank, but when you get to the boss (read: important) fight the other tanks are sidelined. This causes a bit of an inferiority complex in the additional tanks.

This will be alleviated a bit when Blizzard implements the “dual-spec” system, as dps/tanks will be able to switch back and forth, and the tanks won’t feel like such a lame duck when they are attempting to dps for boss fights.