I refuse to watch dramas that are overly dramatic or sad( I usually find them annoying if I try to watch them) -like Koizora( I was barely able to finish the movie... I wouldn't touch the drama with a rag on a stick).
Another type I cannot stand are remakes with different actors, if I really liked the original cast and drama. That would be Ikemen desu ne, Hana Kimi Taiwan, To the Beautiful You, Boys over Flowers, Meteor Garden, Operation Proposal... Some I tried to watch, but 5 minutes into the drama I would be like: "NO! NO! NO!.... What am doing here?" and turn it off.