Some friends and I will be visiting Rome and Florence in May for about 8 days. We have been to several times; however, it's our friends' first time. Any suggestions on where to eat would be greatly appreciated. We'd like some choices for economical lunches and then a few not-to-be missed dinner spots at affordable prices, trattorias, and maybe a one higher-end meal in each city. We don't have names of places from our previous visits unfortunately.