I have used gildan g200 (6.1 .oz) it ok but you have to use a lot of pretreat to get better white base. I have also used gildan g500 (5.3 .oz) it seems to work good with the pretreat get better white base. I also used gildan g640 (4.5 .oz). It was ok but it too sucked up the pretreatment.
I have also use alstyle AAA 1302 (6.1 .oz) it a lot like the g500 where it uses less pretreat.
And I used AAA 1701 (5.5 .oz) super soft tee. Out of all the shirts I have tried these feel the best some of the most comfortable shirts. But it was worst then the g200 it was a vampire it suck the pretreat dry.
I used a few others as well but wasn't impressed so I didn't feel I should mention them. Plus I find more people that stay away from the others like Hanes, FOTL, and Champion.
My printer is a Anajet mpower 5 and I use the pretreat they recommend and at the proper 1:1 ratio.
As far as fit. Most of my customers have like the AAA shirts it has given them more room and length. For the guys 2xl and above.
On another note if anyone has used a different pretreat and had good success please let us no. And what shirts you have used.