Even though it's been around since 2006, the second-generation Audi TT remains a a beautiful piece of design. And it still drives really well, too. Available as both a coupe and a Roadster convertible, Audi's small sports car is hardly the most practical on the road, but few cars can match its blend of prestige, quality and comfort. Equipped with Audi's 2.0 TDI diesel engine, it's also relatively cheap to run for a car with this level of performance and driving thrills. But for real excitement and performance, the range-topping TT RS offers supercar-matching acceleration that is truly exhilarating. The Audi TT comes in three main specifications – entry-level Sport, mid-range S line and top-of-the-range Black Edition.