What's the best way to tell my boss I'm going to quit?

“Boss, I’m going to quit.”

You: (Irritate the boss)
Vexed Boss: “That’s IT. You’re fired!”
Smug you: “You can’t fire me, I QUIT”

Go in and tell them that you have been offered a better oportunity, and that you are going to take it. tell them that you have enjoyed your time with them and that you will keep them in mind for future work should the new job not pan out.

its a long shot, but doing it that way may actually allow you to go back in a month if it actually does not work for some reason.

Well since you have to put your termination in writing you have a very good avenue to say what needs to be said.

I would say that you are officially putting in your two weeks notice and that your decision is two-fold. First is that you were, out-of-the-blue offered a job with more career opportunity and better pay. Second is that since you were cut out of the career opportunity in your current position you see this new position as an even better choice.

I don’t think that including the second part is “petty” at all. It is a clear reason you are choosing this job and they should know for future reference. However if you don’t want to include that then I say go with @poisonedantidote response.

Be a professional about it.
Carry yourself with dignity, give your two weeks, and work the last two weeks harder than you worked during your first 2 weeks.

With a positive mindset, thanking he/she for their input. Never burn bridges and remember that what you did not like, others still need to tolerate, so be gracious to a fault.

Just write a normal letter of notice, thank them for the experience, wish them well, and leave when your 2 weeks are up. Don’t mention your disagreement unless they start to make counter-offers; if they do, you are in the position to ask for what you really want.

I’m with dannyc

Do not burn any bridges, you never know.

Good luck!

What @poisonedantidote, @dannyc and @pdworkin say. No point in reminding the boss of how you were cut out of that project. Save it for in case they try to change your mind about leaving and use it as a negotiating point.

“I’m here to give you my notice. I’ve been offered a wonderful new opportunity, and I’m ready to make a career move. My last day is ~~. Thank you for all your help and support in the past.”

You let her know via a formal letter of resignation… the short term difficulty that it might cause at your current job is really not your problem.

It’s nice that you’re willing to consider them and whatever issues they may have… but you have to have you best interests at heart. You can trust that they have their best interest at the forefront of their actions…