OMICS International hosts a list of peer-reviewed journals. Journals are viewable by subject such as Chemical Engineering, Social and Political Science and Medicine. Medical Journals are further subdivided into subjects like Infectious Disease, Clinical Research and Medical Ethics and Health Policies.
They give most journals a rating called an Impact Factor, or IF. It's a rating out of five and represents the relative importance of a journal within its discipline. These are calculated by looking at the amount of citations the journal receives in recent scholarly articles. They also list the most highly accused journals for each subject. Wikipedia also has a partial list of peer-reviewed journals.