Our one year dating anniversary!

My boyfriend and I are coming up on one year together which may not seem like a big deal but it really is to me. He’s put up with so much over the year and has proved himself over and over. I love him so much and we’re already thinking about spending our lives together. The day of our anniversary we’re going to the aquarium (my favorite place to go) but I have no clue what to do for him! I’d like to get him a gift and I’ve asked him what he wants to do or get but he says over and over again that he wants to do what makes me happy and wants to see me be happy (hence the aquarium.) But I still wanna get him something or do something for him. Any ideas? I already hand write him letters which he likes to receive. He doesn’t really need anything or want anything. Our sex life is great. I already wear lingerie a lot. I really have no idea what to do.