Web Browser: Chromium
Email Client: gmail
Terminal: terminator
IDE: Sublime / VSCode
File manager: terminator
Basic Text Editor: Sublime
IRC/Messaging Client: irssi
PDF Reader: Chromium plugin
Office Suite: Libre office (I'd prefer Microsoft one)
Calendar: Google calendar
Video Player: vlc
Music Player: YouTube :D
Photo Viewer: basic gallery
Screen recording: -