Obama has been a far more effective President than Clinton ever was. So, Obama.
...why do you think so?
I've been pleasantly surprised at his skill at working with Congress in his first two years, and during the lame duck session. He got a lot more legislation through Congress than Clinton, whose health care initiative never even made it out of committee. If he were to win reelection I have little doubt he'd be able to go back and hammer out a deal with Boehner to cut the structural deficit, likely based around the deal they were close to in 2011.
I think Clinton was a center-right president though. I'm assuming most of the bills Obama got out of congress were during the Democratic majorities in Congress 09-11; Clinton probably didn't want to sign a lot of them, and didn't really lead from the front lines until post-94.