If Obama has done right things, I suspect most of them are with his daughters and wife. There has been a continued effort to prevent significant terrorist activity within the United States with the marked success of preventing an Iranian assassination of a Saudi on American soil.
There is the failure to identify the Tsarnaev brothers as a threat, though that is a systemic problem related to the unwillingness of the government to identify the threat as Muslim and not merely generic terrorism.
He has signed bills passed through Congress, the majority of which originated in the "EVIL" House of Representatives - thus confirming that which the White House does not want widely publicized, Congress does something.
If deciding whether I would view Obama positively or negatively, in totality, I would make a Franklin list. I suspect the final conclusion would be predictable.