Just occurred to me that there might not be one
Saiyan saga has kaioken which isn’t technically a form but may as well be Frieza saga has super Saiyan, cell saga has super Saiyan grades and super Saiyan 2, buu has super Saiyan 3, bog has god, then blue, blue evolved and ui
Am I missing one?
That was Cell saga, Gohans the first to get that form which he does against Cell. You get variations on the first Super Saiyan form which is Super Saiyan Second Grade and Third Grade, which are achieved by Vegeta and Trunks, but its still considered just Super Saiyan. Goku and Gohan achieve Super Saiyan Full Power, which is mastery over the base Super Saiyan form.