We changed to an Audi A4 Avant 130PD after my Edition 30. My wife does approx 15k per year and it made finacial sense in the current MPG stakes and fuel costs.
The A4 averages 42-46mpg which is superb for a heavy car. My Edition 30 after all of it's mods averaged 29-30 mpg and less the 25 mpg with spirited driving.
It really makes sense on a daily / yearly running comparison.
My fun comes from a well fettled 2 litre 16v Golf with over 200bhp a diff etc etc which gives me much amusement on track.
I've just got rid of a E90 330D....that is a properly quick car with good mpg too....highly recommended.
When things have settled I will venture back into petrol but for long hall stuff you can't beat a TDI.
I'm going looking for an S-Line A6 2008 2.7 or 3.0 tdi with LED's at mo. I've not tried the 2.0 TDI but the A5 also floats my boat although they are still pricey.