Input Budapest into the Quick Search on this site. 'Centrum' and 'Emke' are very central. 'Aero' is actually 7km out near the airport. 'Váci út' and 'Heroes Sq.' are on the edge of the centre.
Official and efficient service. Take Zona taxi from the booking stand outside either of the airport terminals. Approx €24 to the city. City to the airport for around €17.