Peruvian, Japanese, Korean, Italian, German, Chinese, Mexican, Vietnamese, Cuban and Spanish would be my favorites. Indian is okay at expensive places but never found good cheap Indian food.
unfortunately, the indian food that we tend to get in britain is often all the same stuff (literally from the same pan) with different added things to make the different dishes!
Italian- I love the Olive Garden. I also like Chinese Chicken Fried rice (depending on which chinese restaurant I get it from.
I don't go out and eat a lot, we cook at home but If I'm going to open a restaurant I will do Italian because people love it, and Chinese restaurants are growing everywhere now.