Reports I've seen suggest the following:
1.4 TFSI manual - around 47mpg (45mpg COD)
1.4 TFSI S Tronic - around 41 mpg (44mpg COD)
1.6 TDI manual - around 57 mpg
1.6 TDI S Tronic - 51 - 54 mpg
Also bear in mind, not sure if the 1.6 TDI is part of the VW emissions scandal (it may well be) but if it is the software fix may end up changing these figures do the worse.
My pick of the bunch would probably be the manual 1.4 TFSI though I'm not really a diesel fan if I'm honest!