The last horror film I watched was Mirrors and I couldn't look into one properly for a few weeks and I sometimes hesitate nowadays. I generally try to avoid horror films or if they are on whilst friends are round I just don't watch them (pillows ftw). The thrill of a scare is good at the time but afterwards, my imagination plays up so much. So I'd rather avoid this kind of trauma.
Also, if horror films were silent they wouldn't be half as scary.