Do you live in New York? Do you feel "meh" about Europe? If you answered yes to both of these questions, you should probably book this flight deal, because you don't even have to love Europe to justify flying to London or Madrid for under $450.
Right now, Norwegian Airlines has off-peak, round-trip tickets from New York to London going for around $410, and you can check out the available dates here. Madrid is also on sale, with round-trip fares starting at about $435, which you can see here. But get on this fast, because these prices are literally changing by the second.
This is your chance to make good use of that New Year's resolution and do something spontaneous before the year closes out. This option is way better than, like, just suddenly deciding to eat an entire jar of peanut butter. Peanut butter is good, but you'll likely enjoy Madrid better. Likely.