Sliding Tile Puzzles

• 14-15 Puzzle
• Picture Puzzles
• Tsukuda's Square
• Variants

Cubic Puzzles

• Rubik's Cubes
• Rubik's Cubes?
• Platonic Solids
• Other Cube Type Puzzles
• Wait, There's more!

Other Permutation Puzzles

• Let's Play Ball
• Sliding Tiles in 3D

Space Filling Puzzles

• Tiling Puzzles (2D)
• Packing Puzzles (3D) 

Disentaglement Puzzles

• Uncles Puzzles
• Computer Puzzlers
• Strings N Rings
• Other Disentanglements

Matching Puzzles

• Crazy Games
• Matched Pair
• Instant Insanity

Miscellaneous Puzzles

• Sequencing Puzzles
• Folding Puzzles
• Peg Board Puzzles
• Miscellaneous Puzzles

Novelties

(No, these are not really puzzles, but intersting toys nonetheless.)

• Rubik's Snake
• Magic Tricks 
• Folding Cubes