Cubes in order of difficulty

1. 3 Pyraminx
2. Ivy
3. Wheel cube / Twisty Skewb
4. 2x2
5. 3x3
6. 3x3 mirror
7. 3x3 Fisher
8. 4 Pyraminx
9. 4x4
10. Kilominx

Other interesting shapes:

1. Skewb
2. Barrell / Cylinder
3. Axis
4. Mastermorphix
5. Penrose
6. Ghost
7. Crazy Fisher
8. Ghost Skewb
9. Skewb Ultimate
10. Fisher Golden
11. Square-1