DynaMed gives the best evidence in quick summary format of clinical topics, covering etiology, diagnosis, treatment, prognosis, prevention, etc. as well as providing links to articles. Available via desktop or mobile device, DynaMed is updated daily and edited by physicians. DynaMed does the time-consuming task of searching for the best evidence for you.
UpToDate provides evidence-based narrative style summaries of clinical topics. Also updated daily and edited by physicians, it takes a more directive approach that many users favor. Available via desktop or mobile device. Note: UptoDate is available to select groups only. See this post for more information.
EE+ POEM Archive (available from UCentral) provides best-evidence answers to clinical questions concerning symptoms, diseases, and treatment. Each topic has a "level of evidence" rating and a "bottom line" summary for quick analysis. Available via desktop and fully downloadable to a mobile device.
The Cochrane Library is a group of databases such as the better known Database of Systematic Reviews or the Central Register of Controlled Trials. Each contains different types of high-quality evidence to inform healthcare decision-making. The filtered resources listed above (Dynamed, UpToDate, EE+ POEM Archive,) depend on Cochrane as a main source for evidence.