Located in Vámház Körút 1-3, the Great Market Hall is definitely a place to be seen in Budapest.
I went there today and spent 2 hours there. It is the greatest indoor market of Hungary and the atmosphere there is really unique.
Most of the stalls on the ground floor offer produce, meats, pastries, candies, spices, and paprika, local wines, pastries, fruits and vegetables. The second floor has mainly eateries and souvenirs.
Here are some pics I took of what I liked inside...