Jasper Johns we've mentioned on this page before, and DaVinci many of you will know. Other important ones:
Joseph Beuys (1921-1986,) a german artist important for his drawings, performances, politically reflective conceptual sculpture (among other things- a very rich and complex figure.) A great book is the 1993 Philadelphia Museum of Art Drawing catalogue.
See this good Biography from the Walker Art Center (Minneapolis.)
Cy Twombly (1928-present,) works for sale on Artnet give you a starting point- there is also a good one on display at the Yale Gallery. Considered a painter because he works frequently on canvas, his work is centered on drawing-markmaking. He has done drawings on other surfaces including chalkboards and paper.
Karen Kilimnick (1957-present,) A link to her first survey at the Institute of Contemporary Art in Philadelphia in 2007. A very prominent contemporary artist, draws on popular imagery and nostalgic romanticism, among other things.
Marlene McCarty (1957-present)
Her gallery, Sikkema Jenkins, is located in Chelsea, NYC.
This blog has a great set of images. Giant pen drawings, larger than life sized figures, semi-nudes.
