Well unigene heaven and 3d mark firestrike, firestike extreme, and time spy are the popular ones for mainly GPU benchmarking. Cinebench R15 is popular for CPU benchmarking. User benchmark is also useful for comparing the performance of all your individual components to others with the same components though it can be misleading at times.
Memtest is a tool for testing the stability of RAM it's not really a benchmark. User benchmark will benchmark RAM. CPU benchmarks like cinebench will also likely be affected by RAM speeds.