Over the last year or so, Embarcadero has built a "Delphi Applications Showcase" site at http://www.embarcadero.com/rad-in-action/application-showcase. In the first round, it had mostly utilities. Now this showcase has been extended not only with many more utilities, but also many business applications for vertical markets.
The list of additions was posted by Tim Del Chiaro at http://edn.embarcadero.com/article/41052 and looks quite impressive. There are some tools I use (like WinSCP or HeidiSQL) that I didn't know for sure were written in Delphi. There are applications written by companies I've done consulting for. There are a lot of applications... but there are still hundreds missing. I hope more and more Delphi developers submit the software they've written in Delphi, software of all kinds. For example, some of the most widespread ERP and accounting systems in Italy are written in Delphi, and they are all missing from the list. I guess I should also add some of my apps, even if minor ones!
There was a recent discussion on this very topic on a Delphi LinkedIn group, with the original poster asking if Delphi is actually used for any real application. This long list, even if very partial, is a clear answer.