Obama is a victim of circumstance. Elected in just about any other decade and he'd be one of the greats, no doubt about it.
Recession, climate change, Syria, Libya, Iran, Iraq, Afghanistan, North Korea, Ukraine, Egypt, Israel-GOP treason, insane domestic controversies (death panels and birth certificates), the list goes on and on... I'm having trouble thinking of any modern President who walked into a shitstorm of that ferocity.