good mix of culture, history and party!
Terror museum is a bit confusing as everything is in Hungarian so it's hard to grasp the meaning of artwork etc - would recommend doing a communist walking tour first for some background. Buda side is really nice and has great views! Check out ruin bars and quirky coffee shops! Go on a night cruise on the river! Spend a good few hours at the baths!
Insider Tip:A picnic on Margaret island with a stroll or bike ride in the sun is lovely!