We spent three nights in Prague, where we'd never been to. We were very happy with the Perla hotel: It's perfectly located, between Old town and New town, we walked everywhere, it's only a 10 minute walk to the Charles Bridge. It's "far" enough though not to be bothered by the noise of party goers in the Old Town.
The staff was very friendly and helpful, and offers a very convenient transfer to the airport.
The breakfast buffet is very good!! Lots of things to chose from!
I will definitely stay there on my next stay in Prague!