I'm going to assume US sales:
Golf TDI 2 or 4 door, MFSW and MFD+ standard (steering wheel with buttons and highend display), premium 8 touchscreen radio standard, HID headlights optional, black cloth interior only, sport seats+ suspension only, 17" wheels only.
The GTI is also 2 or 4 door, has HID headlights standard, sport buckets (they are deeper with bigger bolsters). I think the GTI suspension is tuned differently than the TDI's sport suspension but I'm not 100% sure. The GTI suspension is 0.7" lower and the TDI suspension just says "lowered" and "sport". I assume that the sport suspension is different just because of the different weights of the engine and the GTI is stiffer. Also a different bumper, engine (obviously), XDS electronic differential. It also gets MFSW and MFD+ but the steering wheel has red stitching and a flat bottom.
IMO, the new Golf and Jetta sportwagen are the best buys right now, can't go wrong with either. Of course everyone's needs and tastes are different but that's my personal opinion. And the Jetta sedan/sportwagen are nearing the end of their generation so all the problems have been worked out. For all I know, the new assembly modules on the mk6 golf may prove problematic since they are trying to cut costs. It's too early to tell.