I'm so happy that my students finally responded to this question. My incentive really worked. I 'm just waiting for Steven's reply. He replied in another forum. For those of you who are not my students, I also appreciate your response. Anyway, here's my answer to my questions;
The best place I've ever been to in the U.S. is Washington D.C. There are so many things to see and do for FREE! There are tons of museums, memorials, historical buildings, and more. So, if you like art, history, and culture, Washington D.C. is the place to see. As for the best place I've ever been to outside the U.S., I think the Philippines is the best so far. I went island hopping. I went to Boracay and Palawan (islands) and the beaches and rainforest were sooo beautiful. Plus, the people were so friendly and hospitable.
As for the places that I want to visit, I have so many on my list: Amsterdam, Brugge, Madrid, Barcelona, San Sebastian, Interlaken, Paris, Rome, Cinque Terre, Florence, Sienna, Corfu, Ios, Athens, Mykonos, Santorini, Innsbruck, Salzburg, Fussen, Munich, Prague, etc. I've never been to Europe. This summer, I'm planning to backpack across Europe with my friend. I'm gonna work hard to save money, so that I can afford to purchase a plane ticket and a Eurail pass.