Comprehensive Character Tables and Reducible Representation Tool
This site is an excellent, well-organized collection of the chemically relevant character tables. I find it particularly helpful because it includes the cubic functions, allowing you to determine the symmetry labels of the f orbitals in a given point group; these are not included in most of the collections of character tables in general inorganic chemistry textbooks. Additionally, it has a tool that automatically reduces (correctly derived) reducible representations into their component irreducible representations.