In America, we celebrate everything -- National Watermelon Day, National Sibling Day, even National Tequila Day. Certain national holidays pay homage to some pretty obscure things, so it's no surprise that there is a special day in honor of our underwear. Yep, you read right! Happy National Underwear Day!It makes sense, really, to spotlight something so completely crucial to our everyday lives. Think about it: your panties are probably the first thing you put on every morning, the last thing you take off before hopping in the shower, and they serve such an important function. Not only are your undies a super realistic, important part of your life, but they can also be a lot of fun. Didn't we all love our "days of the week" underpants growing up?So today we celebrate National Underwear Day, and in honor of such a magnificent occasion we've rounded up some of our favorite unmentionables for you to fully partake in the festivities.