I will 2nd the suggestion for Cervelo S2. It's definitely an aggressive (was a bit too aggressive for my bad back, so I sold mine), fast bike. Throw on a decent set of aerobars and I think you'll be very happy. I originally went with the S2 (I actually had what was known as a Carbon Soloist, which was rebadged into the S2 the following year), because I thought I would continue doing triathlons. But I was never really able to bring my running up to par due to a chronic lower back condition, so my rides started to become more distance-focused and I needed the comfort of a relaxed geometry bike.