[Effendi]

I'd go with Pannon which has some data bundles too (and the best coverage, in 3G too, and an easy tariff).

It's not so easy to buy a prepaid card in Hungary, BTW. When I was in Budapest 1,5 years ago I couldn't buy it... the main problem is that it seems you must go to an official dealer (Pannon, T-Mobile, Vodafone) and there are really few of them and often with quite short open times. And overcrowded. I wanted to buy a Pannon prepaid card in Budapest and it took me time to find the official shop, then it was totally crowded and I was hungry, so I went to eat a goulash and when I came back the shop was closed (about 2pm). It was Saturday so it didn't open at all in the afternoon and Sunday all day. Then I didn't buy it, since I was leaving Hungary the following day...