The Mysore palace is something else. And Brindavan gardens are pretty great too.
But also, don't be surprised when you see the stark difference between the places you see on Google, vs the majority of the city.
That said, if you get the time, be sure to visit the nearby countryside as well. It's beautiful. Hampi nearby has some really old temples which have a very different architectural style than the much more modern stuff you'll see in the city. And the Badami cave temples. Those are about 1200 years old, and quite marvelous.