The nice thing about World of Warcraft’s Loremaster achievements is that pretty much all of them are account-wide, thus ensuring that my efforts to unlock quests in a zone on one character can play into what I’m doing with my next characters. This is particularly useful for me as I track down the last few zones I’m missing with Allied races. It’s nice to know that I’m cleaning up the edges instead of just doing everything on every individual character.
Of course, not every game has account-wide stuff; if you want to have a beast tribe mount or a mount drop in Final Fantasy XIV, for example, you have to earn it on a given character; there’s no “earn it once, use it forever.” Which can be annoying if you have a rare set of appearance equipment on your main, but you really want to use it on your alt.
On the one hand, making these things account-wide is convenient; on the other hand, the argument could be made that it de-emphasizes individual accomplishments. So what do you think, readers? What should every MMO make account-wide? Mounts? Unlocks? Achievements? Something else entirely?