What to get a girlfriend for her birthday?

take her out and make sure you tell her how special she is no present needed just a card and a day with you is all she needs because she loves you. All that's needed is a card taken out somewhere (trains are usually the obvious public transport-and girls like this mode of transport because you can just sit and relax on a smooth ride). At the end of the day she just wants to feel good and have a nice day! :)