We took the 48 hour Budapest card, and one of the highlights of the card was the free walking tour of the city. We took both the tours - the Buda tour in the afternoon, and the Pest tour the following morning. And it was totally worth it!
Our tour guide on both days, Victoria (Viki) was fantastic. Extremely enthusiastic about her city and country, she took us around the city and showed us everything there was to see, sharing interesting anecdotes along the way. She was also very helpful with suggesting other things we could do after the tour, and so on. Definitely the highlight of our trip!