We went out for V-day when we first got married and hated it! They jack up the prices & cram a few more tables in and the service is usually pretty poor because they are so crowded. For the past 20+ years I've cooked dinner at home. I always decorate with different themes - sexy, romatic, or kid-like. I do a lot of the prep earlier in the week and once hubby goes off to work in the morning, I scramble like mad to get everything all decorated, so that when we both come home from work, the evening is special and non-hurried. That being said, we like to go out to fancy dinners and will do it when it's just a 'regular weekend night' - we enjoy it more that way.
Luckily, neither one of us is super-big on celebrating holidays, so this works for us. Whatever you do this year though, will set the precedence, so just keep that in mind. If you have a girlfriend that is going to be super-disappointed if you don't buy her something shiny or go completely over-the-top, you guys may want to have a discussion about values. Also, show her you're thinking about her through-out the year by surprising her with little "I was thinking about you" moments - even after 20+ years my hubby still does this with a couple of flowers, a hand-written card, or some other small token action (washes my car or scrapes the ice off....just nice little things) -- this is way more special than some marketed holiday.