I have to choose between romantic books and adventure books? I can't choose another genre? Well, then I'd say adventure books, because books which contain only romance are - in my opinion - a bit boring. If romance is combined with other genres like fantasy, thriller or even adventure, it is a lot more interesting. Adventure books are exciting and fun to read, because adventure books are a lot different from real life and I like reading stuff that's far away from real life. That's why my favourite genres - if I don't have to choose between romance and adventure - are fantasy and science fiction (not stories about aliens and stuff, but about the future), because it is different from real life and when you read a fantasy or science fiction book, you can dream about different lives and different worlds from your own, which is my reason for reading books.
"No one is born in this world to be alone."~ (Saul, One Piece.)