Originally posted by SeVeSI was also torn between the two, but according to my database, the much more common move was Nf3.
3. Nf3 seems the most logical move. However the main line in the Chigorin Defence is 3. Nc3. This doubles the attack on d5 and supports e4. If we play 3. Nf3 CHESS will play 3. ... Bg4 and maybe force an exchange later on that could ruin our kingside pawn structure.
I vote for 3. Nc3.
--SEVES