My first frame was a surly - durable and steel, plus I really liked their no frills approach. Found it on eBay for c-h-e-a-p (I used to scour eBay for frames and parts).

Had that for a while, wanted to get another. Hm...went to LBS (Yojimbos) and saw what Marcus had. And then waited for $ to build up. Skitbra went and got a DeBernardi from Marcus after much frustration in geting a Soma. I really liked the frameset upon seeing it built up, as well as the materials (Thron tubing). The paint, well...not the best. Whatever, that is a small thing for me. I had also been buying parts here and there off of eBay. So there you have it. The evolution of idea, design and implementation for building vs. buying.
On the other hand - if you do not have the time to do this, go with a prebuilt, like the bianchi. Most people I know that have them really like them.