I was surprised how much the city reminded me of Minsk (my home country`s capital)! Similar architecure but much more graffiti on the walls. :-)
After spending 5 days there, I can say that my favourite place is definitely Szechenyi baths: went 3 times and LOVED it!!! Massage was great also (2500 HUF (~$11.6) for 15 minutes).
Second most interesting place was ... the Zoo (right next to the baths).
Loved the weather - very mild climate. Although it was raining every now and then.
I noticed the city does not have a lot of night life - after 8-9pm the streets are kinda empty..
People spoke English just enough for us not to feel lost. Everybody was very helpful and we did not have problems at all.
I must say that 5 days in Budapest was too much. 2-3 days would be just enough I think.