Sokoban++ - A free Sokoban player with 50 built in levels.
Simple Sokoban - Simple Sokoban is a (simple) Sokoban game aimed at playability and portability across systems.
Sokoban YASC - A modern free Sokoban player
Sokoban Online - Play Sokoban Games Online.
YSokoban - A classic but still maintained Sokoban player
Sokoban 3D - It's Classic Sokoban, but in 3D!