Depends on Model, Mk5 6 or 7 GTi or R, MK5/6 GTI either 235/35 or 225/35, if R model then it will have to be 235/35 for the 92 Load index rating.
A word of caution, if you decide to go for 235/35/19 in Mich Pilot super sport they come up big compared to almost every other manufacturer, both width and circumference (only seems to affect the 235) and will most likely Rub on a mk5, front and back.
I had BBS CH 8x19 et 50 on stock height with Billy dampers and they were horrendous, rubbed on inside of rear arch liner then with spacers fitted would catch outside lip at the bumper to arch join, fronts rubbed on lock and the worst was on full compression in straight ahead would catch wheel arch liner at the screw position, with only myself in the car, yet the previous falkens the same size never caught anywhere even four up..the PSS was physically the same dimensions when put side by side to a 255/19 bridgestone 050A at ATS.
Unfortunately I have none of the pics left, I had loads saved on my old phone, rookie iphone user and lost them before back up