Wikipedia credits Skype as being written in Delphi. For a good list of other applications written in Delphi, visit delphi.wikia.com. Plus Embarcadero has a dizzying showcase here. The list of software built with Delphi includes Ad-Aware (which I recommend/install on all relatives machines), Beyond Compare (used at work), Adobe Captivate, FinalBuilder, Help and Manual, Macromedia Homesite, TOAD, Total Commander, and many more.
Yes, i read it somewhere that they possibly rewrite the software using C++ later. or maybe it is some other software.