In general Achievements are something I avoid actively pursuing. This also goes for trophies or any other sort of meta marker that game companies come up with. The only exception I have found thus far is World of Warcraft.
To me, achievements are essentially random non story line activities (aka errands) that help extend the amusement of the game. Which makes perfect sense in a MMORPG setting, as the entire purpose of the game is get the player to come back forever more, wasting years of their lives away. It doesn’t matter if the achievements are as asinine as ‘carry four specific potatoes around the world, then cook up a batch of fries, and hand one to each playable race in the game’ because someone out there will have a good time doing it. People always need more to do.
But when it comes to non-persistent games, like Mass Effect+, Diablo+, Portal+, Halo+, etc, I just don’t have any interest in pursuing mostly idiotic goals for a few measly achievement points. Maybe if I felt a strong urge to replay games, this would be different, but as it stands I’m mostly a single play through sort of gal. I really appreciate that some games end.
The other fault with the system is that since developers design achievements and trophies, there is no standard for determining difficulty. In one game three achievements might take forty hours of game time, yet in another game three achievements might be unlocked in the first five minutes. This lack of uniformity makes achievement points an incredibly inaccurate form of measurement. And just like all systems that try to narrow the human experience down to a number, this score fails to accurately represent any gaming experience. So I mostly just ignore it.
Strangely enough, this lack of achievement consistency has resulted in a meta game where people play games solely for the purpose of achievement mining. They literally pick the game not for fun or interest, but only for the ease of gaining achievements so they can boost up their total achievement score as fast as possible.
Not that this is bad in any way; we all find amusement in different things. But my fun is had by simply playing games to enjoy them. The time I spend playing a game is a much better indicator of how much I like it.
There you go! That was a rather long winded way of saying that I sometimes go after achievements in World of Warcraft, but otherwise all the achievements I have are unintentional.