I believe Obama was instrumental in ending the housing/banking crises.
I think he was a better president than I ever expected and his legacy will be better than many want it to be. However, I don't agree that he was instrumental here at all. The mere discovery of the issue made the end of the housing / banking crises inevitable. When a shaky foundation is about to collapse or does collapse, people get to work fixing it. This would have happened regardless of who took office during that 8 year window. There wasn't anything special that Obama did here.
The pending crises was all built up during the Clinton and Bush years and stemmed from the home ownership mandate. Everyone not only has a right to own a home, but they must own a home. Even if they can't afford it! And we did everything we could during those years to shuffle risk around and pretend it didn't exist.
A true visionary would have been one who spoke up in the 1990's and said this is a bad idea. People who can't afford a home probably should save up their money and improve their earning potential, then buy one. But that would stifle growth.
For the perceived "bad" part of his legacy - a lot of our most conservative commentators are lamenting the number of people "out of the workforce" to show that unemployment being so low is a mirage. However they are ignoring an aging population and a return to the idea that a stay-at-home parent can be good for the kids. The fact that more people can retire or choose to stay home for their families is not a bad thing in my mind.
They also say, "He's the only president who never once saw the economy grow at a rate higher than 3% during any year of his term!". To me - that's a big, "So what?" I'd take steady 2% growth over volatile growth all day long.
My biggest complaint is debt / deficit and trade imbalance. So far I like seeing Trump jump on some of this stuff trying to renegotiate with government contractors who see government work as a chance to screw those with deep pockets. However, I question whether this is a bit too micro for the president, who should be focusing on the macro.
I guess he wouldn't need to if our representatives in congress were more responsible. But getting big contracts for their constituents is their job, which is part of why "congress" has a terribly low approval rating, but each member of congress keeps getting re-elected. My representative is great. Yours is horrible.