My favorite for T-Shirt fusing is Pellon 911FF Featherweight.
Also you can go online to Pellon.com and find a chart for all of their fusing/interfacing , and a detail of which product is best for each application. I have printed it out and really comes in handy. The chart I have is for Sew-in and Fusible. I know some people like the heavier weight. Good Luck.