Lily Ledbetter Act made it easier to recover for employment discrimination, and explicitly overruled a Supreme Court case making it harder to recover back pay.
The ARRA was a huge relief bill for the financial crisis, one of the largest bills of all time.
The Credit CARD Act changed a bunch of consumer protection for credit card borrowers.
Dodd Frank was groundbreaking, the biggest financial reform bill since probably the Great Depression, and created the Consumer Finance Protection Bureau, probably one of the most important pro-consumer agencies in the federal government today.
School lunch reforms (why the right now hates Michelle Obama)
Children's Health Insurance Program (CHIP or SCHIP): healthcare coverage, independent of Obamacare, for all children under 18.
Obamacare itself, which also includes comprehensive student loan reform too.
That's a big accomplishment list for 2 years, plus some smaller accomplishments like some tobacco reform, some other reforms relating to different agencies and programs.
Plus that doesn't include the administrative regulations and decisions the administrative agencies passed (things like Net Neutrality), even though those generally only last as long as the next president would want to keep them (see, again, Net Neutrality).