Which NFS is better

4.1 First Generation
4.1.1 The Need for Speed (1994)
4.1.2 Need for Speed II (1997)
4.1.3 Need for Speed III: Hot Pursuit (1998)
4.1.4 Need for Speed: High Stakes/Road Challenge (1999)
4.1.5 Need for Speed: Porsche Unleashed/Porsche 2000 (2000)
4.1.6 Need for Speed: Hot Pursuit 2 (2002)

4.2 Second Generation
4.2.1 Need for Speed: Underground (2003)
4.2.2 Need for Speed: Underground 2 (2004)
4.2.3 Need for Speed: Most Wanted (2005)
4.2.4 Need for Speed: Carbon (2006)
4.2.5 Need for Speed: ProStreet (2007)
4.2.6 Need for Speed: Undercover (2008)

4.3 Third Generation
4.3.1 Need for Speed: Shift (2009)
4.3.2 Need for Speed: Nitro (2009)
4.3.3 Need for Speed World (2010)
4.3.4 Need for Speed: Hot Pursuit (2010)
4.3.5 Shift 2: Unleashed (2011)
4.3.6 Need for Speed: The Run (2011)

in this series, please tell me
1-which has better game play?
2-which has better graphics?