Web Browser: Firefox
Email: Anything simple and lightweight
Terminal: Default GNOME Term.
IDE: Shouldn't be in a default install
File Manager: Anything simple and lightweight + tabs (Nautilus) Basic Text Editor: vi
IRC/Messaging: Pidgin or Empathy
PDF: Default GNOME Viewer
Office Suite: LibreOffice
Calendar: Default GNOME Calendar
Video Player: VLC
Music Player: VLC
Photo Viewer: Default GNOME
Screen Recording: Something full featured?
Additionally:
Maps: Anything supporting OSM (GNOME Maps)
Software Center: GNOME's Software Center