There are a good number of excellent clinical cases with essential history, physical examination, diagnosis, treatment and references to go more in detail. There are also pictures and reports of exams prescribed.
All the material is meticolously archived in a menu you can browse by topic: cardio, pulmo, GI, Nephro, Endo, Hem/Onc, Rheum, ID, Neuro, etc.
The project is developed from 2002 by physicians at Cleveland Clinic or Case Western Reserve University (St. Vincent/St. Luke) Internal Medicine Residency Program and still seems very active. The Editor in Chief, Dr. Dimov, maintains also a blog, a real gold mine for reliable web resources, which I really suggest you add to your personal rss feeds.
The only negative aspect is that there aren't so many comments on the clinical cases: but this is our fault, I think we should be more interactive on the web.