Well, today I have to say the EHD my husband just ordered for me!
But to be honest, I have to say a small chocolate heart with the words "GLAD I DEG" (Norwegian for "I LOVE YOU") that he bought for me when he went to Norway with work for a couple of years ago. It wasn't huge, it was a cheap little thing, but the fact that he saw it, and bought it for me, melts my heart.
It's the unexpected gifts that are the best. It doesn't have to be huge or fancy. It's the fact that someone sees something, and think of me, and get it to give to me, that does it for me. I love the idea of being important enough for someone that I love. The gift in itself isn't as important, if you understand what I mean.