Polo GearsCould be viewed as a variant of the Gear Cube. Here the faces (in this case: the knobs) rotate too.
Punk CubeCould have been named "Pierced Cube".
Puzzles printed on cubeA 3x3x3 printed (not stickered!) to make it look like it was assembled of other cubical puzzles.
Quarter CubeAlso known as Latch Cube II. Another design by the famous Katsuhiko Okamoto.
Qubami 3x3x3"QUBAMI: 3D sudoku with a twist!" The objective is to completely scramble the puzzle from its ordered starting state, so that only one copy of each colour and symbol lies on every row and column of blocks on every face of the puzzle.
Railway CubeAn easier variant of the maze cube with a railway theme.
Rubenking CubeAn attractive sticker variation with confusing properties.
Rubik's 4th DimensionMade in the late 1980's. Four special stickers reveal the orientation of their faces.
Rubik's BankA hollow 3x3x3 which can be used as savings box.