The reasons for it being the best is totally up to you. Most powerful, best looking, most wins, your favourite manufacturer etc. You choose your engine by your own criterias.
Please give a reason why it's your choice and if possible put up a picture as well.
I'll start with a favourite of mine. The Ford Cosworth DFV (maybe not a surprise...)
It's the engine with the most wins (155) in F1. It was used from 1967 until 1991 (it had then become the DFR). It was the engine that powered large parts of the grid in F1 through a long period and became a classic.


Edited to make a poll based on some of the comments. Could only post 20 questions so some had to be left out...
Edited by DFV, 22 October 2009 - 20:56.