Hey you,
I'm sure you know that I appreciate you, but sometimes it's hard for me to vocalize it, so I would like to thank you for a few things in this letter:
First of all, thank you for just putting up with me in general. Trust me, I am aware of how weird I am, and you always laugh and pretend not to be embarrassed, even though I know that you are sometimes when I sing my sentences in public or make really nerdy jokes that nobody even understands. Also, I appreciate that you never ask me to lower my voice even though it's twice as loud as everyone else's.
Thank you for cheering me on in everything that I do, whether I succeed or I always know that I can count on you to be there to tell me how proud you are with even the smallest of accomplishments. On the other side, when I fail, I know that you will be there with that same goofy smile and a hug to let me know that everything will be okay. You make me feel good about myself no matter what is happening in my life. That makes you a pretty cool person.
Thank you for letting me cry on your shoulder about the hard things, and sometimes the trivial things. I know that I'm emotional and that sometimes I overreact, but I cannot express in words how much it means to me that instead of judging me or urging me to talk about it, you just let me cry. Every time I am struggling with something or when I need someone to talk to, you are there with open arms, and that is one of the biggest blessings in my life.
Thank you for being a part of my family. One of my favorite things about you is that you are just as comfortable and respectful around them as you are with me. In my eyes, the approval of my family is not easy, and you achieved it with flying colors by being nothing but yourself. I am so grateful for your respect so that I can spend time with all of the people I love without having to worry about bickering or awkward moments.
Thank you for being my best friend when I needed it. When friends would come and go, and when people especially sucked on some days, you were able to be the friend I needed and put the role of a boyfriend second. I've been able to go to you when I need honest advice, and you know when you need to answer as an honest friend, but you also understand when you need to answer as my significant other (AKA "you're obviously right"). You can shift with my feelings, which is more than I deserve sometimes.
Thank you for giving me the privilege of having you as such a significant part of my life. You are so kind and easy to spend time with. I always thought it was a little lame when people say, "time flies when you're having fun," but when I get to spend time with you, it really does seem to go faster than when we are apart. I'm so glad that I found you.
Finally, thank you for just being you. I love you.