The gothic towers that tower over the old square are just magnificent. They are easily recognised as Prague architecture and unique in that sense. The square is large and gets large crowds but we still found getting around easy. I recommend spending the time to wonder the alleyways and cobble streets. There are great finds only a street away from the main square.
Personally, I had the best of experiences in Prague. It has the perfect combination between culture, architecture, entertainment, outings and people. A walk through the old town of Prague is a must. Nothing stands out in particular. everything is really beautiful and interesting.