Use this resignation letter template as a guideline if you really want to show appreciation to your boss and share specific memories of your time at a company.
Dear Mr./Ms. Bossname,
Where to start? I can't believe that my time at this company is coming to an end in just two short weeks. I feel like I've grown a lifetime in just three years.
You have been an amazing boss and made a chaotic startup feel like home. Through your example, I've also learned what great leadership looks like. You command our team from a place of respect, not fear. I hope that every future boss will have even a small portion of the qualities you display.
I want to say a few words about the team. Pam is amazing! She makes the front desk run like clockwork and has gotten me out of more jams than I can count. Give her a raise! I wish I could bring Jim with me; his sales savvy is top-notch. As for Dwight, I know he can be a pain in the you-know-what, but at the end of the day he really had our backs in the TPS debacle.
I truly feel that I have built lasting friendships during my time with the company. I would love to have you and your partner over sometime. And, of course, you could always use my help with your golf game.
Keep in touch, boss!