1.8T. 130PD 150PD IMO 
Agree 100% 
As above really. My brother has the GTi TDi 150bhp, and I have the GTi 180bhp (non anniversary). Mine is more refined to be honest and the power is obviously over a wide rev band. The diesel to drive is nice and torquey, but I find it can get tiresome, as in too much all at once! I get 40mpg on a run, my brother gets 50mpg but then diesel is 10p litre more at the pump.
He does gain on the tax though. Mine £210 a year, his £120!
Mine has been re-mapped by R-tech and it really shifts now and the mpg has gone up!

The 130bhp diesel is the more reliable than the 150bhp. the 150bhp can suffer from Turbo failure and camshaft issues but these can effect random cars. The oil changes and spec of the oil is the all important bit!
I have also owned the V6 4Motion and while this was a nice cruiser is was in no way as good as the 1.8T. The only nice thing from it was the sound, but the down side was 23mpg around town!