State Your Intent. The whole theme of your resignation letter is the statement that, well, you resign. You don't need to play coy__the time has passed for you to fish around for a counteroffer if it's gotten this far. At this point, you've made your decision to leave, and this letter needs to reflect that.
How to write an excellent resignation letter. Whatever the language, the sentiment is the same: I'm outta here. However, as a professional person, you need to express that maturely and firmly__ideally, one that doesn't alienate anyone at the job you're leaving. I'm sure we all have that fantasy where we tell off everyone who wronged us on the way out the door, but that person in the fantasy/movie/TV show never seems to have to live with the consequences afterward.