My girlfriend and I have been together for more than a year and have lived together for about 6 months. If I could take her anywhere I would love to take her to Martinez, California where I grew up (ages 6-12). I haven't been there since I was a young boy and would love to show her the places I went to school and the house I used to live in.
I bet most people would choose a romantic tropical holiday but that wouldn't be as great for us. When my girlfriend and I fight or have issues it is because we have no money and are in an unfamiliar setting...sounds exactly like a tropical holiday to me! We get along much better when we are together and learning about each other in a relaxed and engaging way.