National Art Gallery [wikipedia]
There are a handful of twentieth century Bulgarian superstar painters; unfortunately their English names are rarely Google-able and the museum has a strict ban on photography, which I think is a poor decision as some photos could spread the word about these obscure masterpieces.
Ivan Boyadjev - "Street in Karisruhe" (1923), "The Lent", "Townscape from Nuremberg"
Vladimir Dimitrov - The Master is his given title in Bulgarian art. He has some presence on the web, but his masterpieces remain safely unphotographed in the National Gallery.
Stephan Ivanov - "Nocturne" (1921)
Umberto Chiodi - Drawing and painting in the romantic style of Christian religious art combined with the playfulness of children's books on an intimate scale, his psycho-grotesque visions are captivating.
Dimitar Arnaudov - The National Gallery's special exhibition hall was dedicated to this painter's retrospective. I found his work to be bold and captivating. Of course, his best work is locked in the no-photo closet.
Sofia Art Gallery
In downtown Sofia this simple one level gallery is currently showing Bulgarian painters' self-portraits. The variety and quality of the images was astounding. Two really blew me away.
Krassimir Tsanov - Self Portrait (2006)
Ivan Obretenov - Self Portrait (2006)
My final plea: Museums! Allow non-flash photography or die of irrelevance!
360 Degrees Bulgaria
"An emotional message of the need to take care and preserve natural environment. The exhibition presents 120 aerial photographs by Alexander Ivanov taken in the course of 8 years from a delta wing and paraglider."
Sofia Street Art
The city streets are covered in graffiti. Much of it dwells in tags, the human equivalent of piss-marking your territory, but a few well done drawings light up the concrete.