My WAR calculation is a combination of Baseball-reference and Clay Davenport; I believe it to be the "best" WAR number available for historical comparison. 8 WAR is an MVP quality season. The record is pythagorean adjusted for 162 games.
2012 88-74
C Buster Posey 7.95
1B Brandon Belt 2.4
2B Ryan Theriot -.35
SS Brandon Crawford 2.95
3B Pablo Sandoval 3.25
LF Melky Cabrera 5.3
CF Angel Pagan 5
RF Hunter Pence .1
LF Gregor Blanco 1.4
SS Joaquin Arias 1.55
2B Marco Scutaro 2.35
C Hector Sanchez .3
RF Nate Schierholtz .65
2B Emmanuel Burriss -1.25
1B Brett Pill -.25
SP Matt Cain 5.25
SP Madison Bumgarner 3
SP Ryan Vogelsong 2.6
SP Tim Lincecum -2
SP Barry Zito .25
RP Santiago Casilla 1.25
RP Sergio Romo 3.05
-88 pythag wins...and the second World Championship in 3 years. Posey comes back with an MVPQ season, the best catcher season in all 130 years of Giants baseball (and it's not close). Cain throws the first perfect game in 130 years of Giants baseball; Giants dominate the All Star Game then lose Melky Cabrera, who had been their best player in the first half, for the last two months of the season on a drug suspension. The Giants were down 2 games to 0 in the NLDS and beat the Reds, down 3 games to 1 in the NLCS and beat the Cards - then swept the Tigers in the Series, Pablo Sandoval hit three game one homers.