Zaha’s work is great. I love her bold style. I got to meet her once. Interesting woman… I hear she is really hard to work for.
I have always liked some of the paper architects of the last 30 years. Architects like Lebbeus Woods and John Hejduk and Lars Lerup and Steven Holl. I love good design too, but I think I love some of the stories that are behind these amazing designs that never get built. Zaha has some of that too. It is a lot more interesting to think of architecture in that way than it is to think about spec office buildings and strip malls.
For those of you that don’t know who I am talking about… this is an example of Lebbeus Woods’ work:

As far as my favorite building, that is a harder one to answer. But I visited the Salk Institute not to long ago, and it has been a long time since a building inside the united states moved me like that. The Salk Institute is designed by Louis Kahn, arguably in my mind, the greatest american architect. I also never miss a chance to see the Arab Institute when I am in Paris designed by John Nouvel.