I can tell you right off the bat that my favorite Aston Martin is the V12 Vantage. It's a manic machine with a short wheelbase and a monster motor. It's not the best Aston though, because it still suffers from the same issues that affect all of the current crop of cars from Gaydon. The center stack is fitted with horrible buttons that actively work to do the exact opposite of what you'd like them to do. Additionally, AM vehicles fitted with the SportShift II gearbox need serious help.
The Vanquish, however, is a new breed of Aston machinery and it shows that the engineers across the pond have been listening. The result is an Aston Martin that works, and it works every day. This is the grandest of grand tourers... and it might just be the best Aston Martin ever made.