I'd take the S3 over the other two at that price without even thinking twice. I feel it's just more special and complete as a package. Turbocharging helps the decision along for me too. I like turbos...

[...not that I'm not fond of naturally aspirated engines either - I'd wager that the 130i has the best engine in this company too - it's just that I've become accustomed to the feel of them over the years as every car I've owned for the past 7 has been turbo'd.]