ReSharper

Ctrl+Shift+Space Smart Code Completion, Complete Statement
Ctrl+Alt+Space Import Symbol Completion. Unlike Symbol Completion (which only completes types accessible at the current location), ReSharper displays all types that match a specified prefix regardless of what namespace they belong to, and automatically adds the appropriate namespace import directives when necessary.
Alt+Enter Importing Namespaces
Ctrl+P Method's parameter info
Ctrl+/ (for line comment) or Ctrl+Shift+/ (for block comments in C#).