There are 3 types of armor used.
1. The early saiyan armor with shoulder pads-used by the Saiyans(other than Goku and Gohan) in the Saiyan Saga.
2.The armor in the Freeza Saga that Bulma creates for Gohan and Krillin for the fight on Namek.They look th same as the Saiyan Saga ones.
3.The ones without Shoulder pads in the Namek Saga and the Android Saga ..more info soon..