Who are the top UI designers on the web today?
pantalones: i think the names of the top 5, 10, or 20 designers aren't public because they are busy working on uis instead of promoting themselves on the web.  it's all a matter of opinion.  a lot of the people mentioned below have 1-2 things under their belt, excepting some of the more seasoned folks like bowman, vinh, and miner.  the reality is no one person is responsible for a great ui.  it's a confluence of talent. the only reason you know about any of these products is because the talent of multiple individuals produced it.