Citroen C6 3.0HDI Exclusive – 237bhp

The C6 makes a strong case as an alternative to the German trio and its 3.0-litre diesel, the only engine option for the range, is surprisingly eager without hitting your wallet too hard (it manages a commendable 38.7mpg). Where the C6 does fall short is on the depreciation front, though that does mean some great bargains on the used market.