Snow, for my 30th birthday.

A close friend knocked on my door holding what I at first thought was a white package. He told me to come outside, so I did. He'd gone hiking that morning and ran into snow so (knowing I loved snow but rarely got to see it) he backed his truck up the mountain, filled it full of snow, and unloaded it into my yard before he came and got me. We built a snowman and had a snowball fight.

Most unique and thoughtful gift I've ever received.