Man, aluminum just hit it's current zenith not 10 years ago. There are quite a few aluminum bikes that ride like a DREAM, and can be had for a song.
My daily commuter is a primo 1999 Pinarello aluminum bike that rides to a degree that is truly mind-blowing. Any Cannondale CAAD from 3 on up is an awesome ride too.............
I don't post much on first time roadie requests because everyone seems to want brand new, but this is a cold hard fact...........a world class bike made 15 years ago beats the tar out of a middle of the road bike made 15 minutes ago. Most folks have never ridden "state of the art" stuff, and have no idea, but trust me, I know what I am talking about.