Best PSP game of 2011, yes.
Best game in 2011, no.
But that's just me.
Don't get me wrong, I loved Peace Walker all my heart, but I thought there we some better console games out there (i.e. Portal 2, Uncharted 3, Arkham City, and of course, CoD KIDDING!.)
Edit: wait, didn't PW come out in 2010?