Merck Manual worked best for me when I was an MS1 and we had problem-based learning cases that were very clinical. We all barely knew anything and it's helpful in that regard. I've never used it on wards b/c I used epocrates and that pocket medicine manual. Epocrates is the giver of life and will become your best friend. If I need to look something up I go to UpToDate [or the hated DynaMed, which our school used to replace UpToDate but enough staff got honked that we're going back to UpToDate]. Emedicine is I think a better encyclopedia-type resource that I used pretty frequently 3rd and 4th years- it's kind of like wikipedia's older and more responsible sibling.