I think the answer partially depends on where you are in your studies? Are you just starting? If so, you should focus on materials like PR 2007 and the Kaplan general book. If you are farther along, there are other materials such as the LSAT CR book, which is supposed to be the bible for CR. You could also try the Kaplan 800 book or the MGMAT CR book. For RC, sorry but I never used a RC book. Hopefully another member can make a good suggestion.