We've sound stars almost twice as large as what was previously believed to be the maximum possible size for stellar bodies.
The largest star ever found is 300 times bigger and 10 million times brighter than the Sun
That and we've discovered that the proton is lighter than we thought--a violation of what we knew about the universe and its constants.
I like these discoveries. While they don't threaten to overthrow any scientific paradigms, they are reminders that the universe is a complex place, and that we've got a ways to go before figuring it out.