My MBA 1.6/80 is the machine I take to work with me. I teach college and walk to work, so it's nice to have such a lightweight machine to carry with me. At home, I use my 24" iMac Aluminum unless I'm watching TV, then it's time for the Air.
I have to add that I've been using Macs faithfully since 1992, desktops and laptops, and the Air is easily one of the best Macs I've ever owned. I love this thing.