Which 1 will be the best insulator?

Aluminum foil, cotton wool shredded paper or foam.

Put it in order from best to worst would be nice

If possible can you explain why it was so effective?

Ok, here it is:

Foam, shredded paper, cotton wool, aluminium foil.

An insulator is one which prevents heat from being transferred.

Foam traps air in the form of bubbles, and air is a good insulator.
Shredded also traps air, but the air can escape, carrying heat away, even if that's really small.
Cotton traps air less than the above materials.
Aluminium foil is a good conductor, and hence, bad insulator.

Hope it helped! :)

PS- Remember that air is the real insulator in each case, and it is used in many ways, in 'thermos', between the walls in cold countries, etc.