Free Useful Software template

GIMP (GNU Image Manipulation Program)

Name is self-explanatory.

Best free Photoshop alternative.

Honorable mention: Paint.net

7-Zip

For compressing and uncompressing files.

Better than WinRAR in every single way.

Honorable mention: PeaZip

MPC-HC

Lightweight media player. Superior to VLC.

Honorable mentions: VLC, Deluge, PotPlayer

qBittorrent

Very lightweight, stable, full-featured torrent-client.

Honorable mentions: uTorrent 2.2.1 , Tixati, Miniget

ShareX

Take screenshot, share it everywhere.

Support for direct Imgur upload.

Honorable mentions: Gyazo, Puush

OBS

Screen recorder. Better than Fraps.

Honorable mentions: Bandicam, Shadowplay

F.lux

Changes screen color temperatur to a warmer color. Extremely comfortable at night.

Honorable mention: Redshift

LibreOffice

Full-featured office suite. Decent MS Office alternative.

Honorable mentions: OpenOffice, GDrive

VOID Tools Everything

Incredibly fast, lightweight search engine TOOLS for local files.

Honorable mention: Windows Explorer

IrfanView

Lightweight image viewer with a lot of options and features.

Honorable mentions: Picasa, XnVlew

Pidgin

Universal chat client. Includes Hangouts, Facebook and IRC.

Honorable mention: Miranda IM, Trillian

Sumatra PDF

Free PDF reader, that also supports comic archives. Much better than Adobe Reader.

Honorable mentions: Foxit Reader, CutePDF

TeamViewer

Help or get helped remotely by sharing your screen without any hassle.

Speccy

Basic system information tool.

Nice for troubleshooting.

Honorable mentions: CPU-Z, HWmonitor

Audacity

Easy to use multi-track audio editor and recorder.

foobar2000

Highly customizable, lightweight music player.

Honorable mentions: AIMP, WinAmp, WMP