Artist, architect, humanitarian, and extremely inspirational for me ... his tangible works speak of a deeper consideration of How People Are than most such things. For most architects, a building is considered in the context of what is around it. Hundertwasser clearly considered buildings in terms of the relationship between the occupants / visitors and their experience of the world.
For example, the Hundertwasser Haus in Vienna, Austria has floors that roll and pitch underfoot. They are not the level, smooth expanses nearly every other building gets. He felt that we are not meant to go around plodding one foot in front of the other on pavement at all times, but that we are supposed to have to interact with the floor, and that to do that properly, it needs to have a micro-topography. The bathrooms at Hundertwasser Haus are trip, by the way. :D
My sense of appreciation and kindred spirit was cemented by his Window Dictatorship manifesto, which spells out how and why we all need to be in command of our windows, even if we live in the most dismal of slums. He says the sameness of windows in architecture is a kind of apartheid, a racism of architecture, which suggests that the people inside the windows share a sameness with the windows. That is to say, if you live in an apartment block, and your building has 100 same-y windows on the street, the implication is that 100 same-y occupants live behind the windows ... that we gain an identity aspect simply by the facades behind which we dwell. Read the whole document, and spend some time thinking about what he is saying. It goes far beyond aesthetics, but it also informs aesthetic.