You can watch the films first. I watched all the Harry Potter films before reading the books. Except Deathly Hallows. I think that was a better idea. Because books give details. You can get something more when you read it later. But in a film if you know what is going to happen especially if a plot twist or mystery is involved you may not enjoy it as much as when you are fresh. Thus, one can get the best enjoyment. My cousin who happens to be a bigger Harry Potter fan then me suggested the opposite. Can't recall her line of reasoning.
Though that's upto you. Reading a book takes time. But watching a film is relatively easier. So, people may procastinate and in the end do none of them.
About Enchanted's Amy Adams character let us agree to disagree. Cool to know you already think Shaun of The Dead was great. I tried to show 'Shaun of The Dead' to my cousin, the same one i mentioned and she disliked it. I was surprised. Someone not liking Shaun of The Dead. I changed my plans of ever bringing up Hot Fuzz. That's my favorite Edgar Wright film. Baby Driver would be 3rd or 4th to me depending upon the day you ask.
Do check out Before Sunrise someday, if not in the near future. People love Titanic because that's a great movie. Even though with time a good number of people have grown to dislike it. Similarly, Before Trilogy comes up in discussions whenever the 'best trilogies ever' discussion takes place. I have seen only the first and loved it. Its decidedly 'unromantic'. And with that its one of the best romantic films i have seen. The first time i used romance as in romanticized. Second one as in romance genre.
I think you will enjoy Princess Bride and Some Like It Hot. They were just too good. The Big Sick is also very good. I don't remember much about Kate and Leopold, except that i liked it and it involved time travel and fish out of water elements. Brooklyn is a different kind of film. I loved it. I can say that much. The romance aspect of that film fits into those conditions i think. Also, for the rest of them.