Urs Fischer specializes in making jaws drop. Cutting giant holes in gallery walls, digging a crater in Gavin Brown's gallery floor in 2007, creating amazing hyperrealist wallpaper for a group show at Tony Shafrazi: It all percolates with uncanny destructiveness, operatic uncontrollability, and barbaric sculptural power.

All of Koons's best art - the encased vacuum cleaners, the stainless-steel Rabbit (the late-twentieth century's signature work of Simulationist sculpture), the amazing gleaming Balloon Dog, and the cast-iron re-creation of a Civil War mortar exhibited last month at the Armory - has simultaneously flaunted extreme realism, idealism, and fantasy.

There's a lot of hate mail from readers. There's hate mail, threats, stalkers... I think that I'm bulletproof every week when I've turned something in. I think, I'm a god.

The reason I love blogs so much right now is that I am seeing more critical voices appear, and that's kind of thrilling. I think a lot of critics in their forties or even their thirties have had their voice scared or trained out of them by the academy. I have nothing against the academy. I think it's brilliant and fantastic, but I also think that it's become almost monolithic. The same way a lot of art looks the same, a lot of writing can sound the same and quotes the same theorists.

Marlene Dumas is one of the two or three most successful female artists alive, if you judge by prices. I've never reviewed her work, because I find nothing in it to get excited about no matter how hard I look.

Appropriation is the idea that ate the art world. Go to any Chelsea gallery or international biennial and you'll find it. It's there in paintings of photographs, photographs of advertising, sculpture with ready-made objects, videos using already-existing film.

'Summer of Love: Art of the Psychedelic Era,' the Whitney Museum's 40th-anniversary trip down counterculture memory lane, provides moments of buzzy fun, but it'll leave you only comfortably numb. For starters, it may be the whitest, straightest, most conservative show seen in a New York museum since psychedelia was new.