Links

Nikoli.com (Light-Up (Akari), Heyawaki, Nurikabe, Masyu, Sudoku, others)

Conceptis Puzzles (Link-A-Pix, Fill-A-Pix, others)

Fathom It! (Battleship)

Yoogi.com (Tree-Tent)

puzzle-light-up.com (Light Up, others)

Logic Games Online (Sudoku, Nurikabe, others)

Mindgames (various)