Normally we order dinner in after the kids are asleep and watch a show together. Very low key. DH brings home flowers for me and our daughter, I give him chocolates or an itunes gift card, and we give the kids candy.
DH and I hardly ever get to spend time together out of the house without the kids. But he's taking this week off before he starts a new job next week. Coincidentally, Thursday is the only day this week that I don't have to work. So we're doing a big date day--we'll have from 8:30 until 3 just the two of us! We'd have the date day even if it wasn't Valentines day, but I think it's extra special because it is.
Not sure what we'll do yet, but I know we're going to go out for a nice lunch someplace and focus on time together instead of chocolates and flowers this year.