Probably very common yet best gift for Valentine's day is beautiful roses. You should include roses even if you are buying any other gift for her.
Girls will never say no to Jewelry. So this become very famous and desired gift for valentine's day.
A beautiful red dress will be just perfect gift for her, no matter whether you are going out for date or celebrating at home.
Perfumes are pretty common gifts too and very recommended if someone is passionate about perfumes.
Think about what your loved one need most, it doesn't have to be a romantic gift, it can be a useful gift for her to solve a problem
Last But Not Least
That's what matters most. You make the valentine's day special. Make it memorable and spend some quality time with your love.