Originally Posted by
E20
Goku and Vegeta when they fight both state that there power is well above Gohan's at the time he fought Cell. It's fresh in my memory, because I just watched it a couple days ago LOL, but Broli was weakened, I think it's generally agreed upon that Broli's gigantic transformation is classified as a whole another level of SSJ.
Actually he is 2nd I think, because even though Future Trunks makes the appearnce of the 2nd SSJ, he attained that in the future 15 years after Vegeta of the future did, it is viewed upon that Vegeta was able to go SSJ before Trunks of that timeline, unless if you are couting Broli being the 1st Super Saiyan, then in that case yes Vegeta was the 3rd Saiyan to achieve SSJ status, but then again the movies are non-canon.