2 stone in two weeks, due to life changing events. It's not really an achievement as such, pretty senseless in retrospect, but was unavoidable.
As for achievements, hmm, lets see...I used to be very active, i actually 'enjoyed' excercise, that was the key. It was part of my lifestyle, not a means to an end. I would burn 1000 calories a day with ease, and think of it as pleasure. The sports i enjoyed, consisted of mountain biking, snowboarding and water skiing. They got me out the house, gave me a deeper appreciation for nature, and being extreme sports (to a degree), it was always thrilling.
Extreme sports aren't only extreme because of the danger factor, but also the sheer intensity of the cardiovascular workout thats endured when doing these kinds of things.
You need to find something that you can find enjoyable, which also helps burn the calories. A hobbie that you could enjoy for the rest of your days, that involved a cardio work out.
The mundane "go to the gym and feel the burn" approach to losing weight, never worked for me. It wasn't enjoyable for me at all, and it wasn't something i could see myself doing for any lengthy period. Although, some people love that approach, as of course, its a great way to meet new people.
You should know that there is no easy way to lose weight, and that short term goals are superfluous.