The Obama admin. has some areas where they are truly horrible, esp. when it comes to quashing/arresting whistleblowers, surveillance, torture by proxy, indefinite detention, and extra-judicial execution. Those are all very, very serious issues, and I don't condone any of those things.
The Bush admin opened the floodgates for the administration's expanding unconstitutional powers. Critics on the left were very clear to say that once the Bush admin. got away with taking these powers that no administration would be likely to let them go, and here we see just that happening. On many fronts the Congress has actually supported or even actively blocked the Obama admin from rectifying them (blocking the end of indefinite detention, supporting surveillance, quashing whistleblowers, etc.).
The Obama admin has overturned a few terrible policies (direct condoning of torture, stem cells, institutionally legalized prejudice, unfairly favoring religious organizations over secular, overt sanctioning of anti-gay policies, gutting environmental protections, deranged economic policies, etc.), and managed to get the quagmires of Iraq and Afghanistan sorted out, but hasn't undone the epic, epic, mind-bogglingly destructive legacy he inherited, or done enough.
I do believe Bush is the worst president we've had in recent history, far worse than Reagan or Nixon, for the sheer number of horrible precedents he set, his lawlessness, and the sheer scale of damage he did on so many fronts, as well as the sheer rank incompetence and cronyism that marked ever part of his admin.
The Obama admin is corrupt, but the breadth and scale the Bush admin was far more corrupt, and corrupting.