Here is a time line and you can have a look at the models and decide. I don't think there is any direct competitor to Canon models they just usually try and trump each other at every turn. Maybe a d80 is close to the same spec.
Digital single lens reflex cameras
Nikon D3, August 23, 2007
Nikon D700, July 1, 2008
Nikon D3X, December 1, 2008
Nikon D3S, October 14, 2009
High-end - DX sensor, high resolution
Nikon D1, June 15, 1999
Nikon D1X, February 5, 2001
Nikon D2X, September 16, 2004
Nikon D2XS, June 1, 2006
High-end - DX sensor, high speed
Nikon D1H, February 5, 2001
Nikon D2H, July 22, 2003
Nikon D2HS, February 16, 2005
High-end - DX sensor
Nikon D100, 21 February 2002
Nikon D200, 1 November 2005
Nikon D300, 23 August 2007[31]
Nikon D300S, 30 July 2009[32]
Midrange - DX sensor
Nikon D70, 28 January 2004
Nikon D70S, 20 April 2005
Nikon D80, 9 August 2006
Nikon D90, 27 August 2008[33]
Lower midrange - DX sensor
Nikon D40X, 6 March 2007
Nikon D60, 29 January 2008
Nikon D5000, 14 April 2009
Entry-level - DX sensor
Nikon D50, 20 April 2005
Nikon D40, 16 November 2006
Nikon D3000, 30 July 2009
