Which diet should I try ?

I really want to lose weight before school starts in August. I already lost about 20 pounds. However, I still have to lose about 30 pounds. I was thinking about doing a yogurt diet ( I love activia yogurt). I have protein shakes at home . I dont like soda, cupcakes, pancakes, seafood, coffee or salad dressings. I am very picky. I also dont like brocoli. I am subscribed to a gym so I would be able to work out 5 times a week. I usually do spinning 3 times a week and then strength training on the other two days. Any help would be appreciated.