I would never give up my diet soda. I don't drink that much of it to worry about the artificial sweeteners. I still think it is healthier than the regular kind with full sugar.
I also would not give up my ranch dressing. I don't use as much of it as I used to, but it really makes me look forward to eating my salads.
Dairy is another thing I will probably never give up. I like cheese and yogurt far too much to remove it from my diet completely.