Tools like Resharper and CodeRush are time savers and a must for fluent development. As they tend to overlap, I settled for Resharper just because of familiarity, though as the following poll shows they pretty much evenly balanced. However both of these has a learning curve and you need to learn few more shortcuts to be effective.
It is a common to inherit from a class or use a type which is in other projects and you need to import them before you can use them. In ReSharper there is Import Symbol (Shift+Alt+Space) which lets type completion much more easily. It also adds namespace automatically when you select a type.