Cardiology: Personally, I think the final pages of Dubins' text copied and put in your coat are quite handy. I have carried them for 2 years. (333-346 of the 6th ed)
GI: dunno. Washington manual is as good as any.
Pulmonology: I found the Washington Manual or Ferri to be good with "The ICU Book" to be a great reference at home.
Harrison's / Cecil just tend to be long-winded for the floors.