I always thought it was funny when care bears preen about downing scripted mobs. Come meet me in the Warzones, my friends. That is where the true challenges lie.
like your pvp opponents dont always do the same things against you and you against them. i am sorry but doing the same instances with the same mobs for the last 11 months and until this game dies isn't "challenging". i know i have pvped, reached the highest rank in games only to be bored going around killing the same classes over and over. there is no new content in pvp only a new stage with the same actors making the same play. but for the under skilled this can be i suppose a true challenge.
back to the op:
i can understand the need to have server/worldwide first achievements and perhaps one day this game will have them. but the games level of difficulty makes such achievements neither something to brag about or to keep quite in some conversations.