Some of the replies make me laugh. Every year is the same, posters telling us that the day is just a made up crap day and they don't need to be told when to show love as they show it all the other days!
Well good for you but it doesn't have to be all the other days OR just Valentines Day you know.
We have always celebrated it and we have been married 42 years. We love each other and show it all the time, often buy little gifts, DH often buys me flowers etc but we still like to buy each other a card and maybe a small present and have a nice meal, whether at home or out.
DH has taken the day off work, as he nearly always does on Valentines and birthdays, we are going out in a bit and then tonight we will go for a curry.
We couldn't care less if it is commercialised or not, we like celebrating it. Of course not all couples do but you need to be in agreement about it.
My parents always gave each other a card for the 68 years they were married and they too were very much in love