After an extensive, in depth personal two year study, I have made the following determinations:
1. Solitaire and Spider Solitaire are not as addictive as Tetris;
2. Tetris makes you feel more alive than Solitaire, Spider Solitaire or Sudoku;
3. Sudoku makes you use your brain in a completely different manner than Solitaire, Spider Solitaire or Tetris;
4. Sudoku can be absolutely agonizing if your brain is not functioning up to par;
5. Solitaire, Spider Solitaire and Tetris all have saturation points at which, once reached, you realize you have done all you can and you must therefore stop;
6. Sudoku, because it requires the use of a unique part of your brain, does not actually have a saturation point at which you must cease to play;
7. Sudoku is both agonizing and aggravating because your brain knows that it can complete the puzzles, but it fails to do so on various occasions, causing sensory overload and meltdown;
8. The finding in number 7 would indicate that the finding in number 2 is incorrect and unsupported;
9. On further analysis, it would appear that the finding in number 8 is rather more complex than that. Tetris, as it requires both mental and physical (to some extent) dexterity, makes one feel alive on a visceral level, whereas Sudoku requires more mental fortitude and the use of logic, and therefore, in the event of failure of one or both of these, there is an insidious emotional response which by its very nature makes one feel something on a completely different level.
In conclusion, Tetris is the puppy frolicking in a field whereas Sudoku is the old dog growling in his kennel.