What will you do for achievements?

Before I started playing WoW I use to play my Xbox 360 and the various games I had for it all the time.  One of the things me and my best friend often did, was go for difficult achievements on games.  I ended up getting 1000/1000 on halo 3 within the first week, and got 1000/1000 on Call of duty 4 Modern Warfare as quickly as I could (damn you mile high club!).  Now that most of my gaming focus is on WoW I have started becoming more and more of an "achievement whore."  All of this makes me wonder, what is it about achievements that make people do so much work for them?

Goals
For a lot of people, achievements can serve as goals that they want to accomplish.  We have all heard the quotes like "A man without a goal in mind, is a man with no purpose" and it applies in game too.  Let's say you really wanna learn how to pvp since you hadn't been into that part of the game before.  You decide your going to work on it until you get your 1k honor kills achievement so that you know you gave it a fair shot.  Sometimes achievements like this can serve as goals for someone to achieve.

Rewards
Probably more often the reason for people to do achievements is for the awards, specefically the mount/title awards.  A personal example for me is I decided I wanted to have a title besides the patient.  So the one I am going for on my druid I'm leveling (he's also my achievement whore character) is the ambassador of the alliance.  Now rep grinding isn't my favorite thing, but I will do it.  I figure this is a somewhat easy achievement to get me a nice new title, so my reason for working on this is the reward.  Often times people will go for long hard grinding achievememts just for the title or mount to show off their hardwork, other times they just might really like that mount or tabard or whatever it is and will put in the effort to get it.  Without the insane title how many people with the exalted's required do you think there would be?  Not nearly as many as there is (I'm sure there would still be some), because in most cases the reason for doing it is for the cool title to distinguish yourself. 

Excuse to collect/do something you like
For some people achievements are used as excuses to collect or do something you like.  With me personally my Druid Algas recently collected ten tabards and will be hitting 10 mounts pretty soon here.  I like mounts and tabards because I think they both look pretty cool.  The achievements for collecting tabards and collecting mounts are great excuses for me to collect these things I like and to be rewarded for it.  There are other people who love the lore so the achievement well read rewards them for roaming around and reading these books.  Achievements serve as an excuse to them and make it seem less "pointless" in some peoples eyes.

Just for the points
For some people they will do a lot of things for achievements just because its an achievement.  I don't really know how else to describe it other then they just want the points.  The perfect example for this is the critter kill and critter /love achievements.  No reward (I think), no real reason, just get some achievement points for it.  For some people, just the fact that there is an achievement for them is a challenge for them to take on, and a way to get more points.  I won't go for achievements I don't enjoy doing, but for some people litlle things like this are a nice break for them. 

Achievements are a great way to motivate someone who normally might not do an activity, or sometimes just good to encourage a break from what they normally do.  I'm personally starting to turn into an achivement whore, but I still won't do something I don't enjoy doing.  On my druid (the character I've been focusing on and working on achievements for) my main goals right now are The Ambassador (exalted with alliance citys), Leading the Cavalry (50 mounts), and 25 Tabards.  Way off in the distance I could see myself going for the Exalted, but that would not be any time soon.  So my question is...

What achievements are you working on?
Why do you do/don't work on achievements?
What great achievements do you have?
What will you do for an achievement?

Happy Healing