1. Steam: PC game download service and chat (10/10)
2. Blender: Free Polygon modeling / sculpting / art/ animation (8/10)
4. Fusion 360: Solid modeling / CAD (8/10)
5. Slic3r (Prusa Edition): An easy to use 3D printer slicing software (10/10)
6. Octoprint: A print server for the raspberry Pi, attached to my Prusa i3 Mk3s for wireless printing and control (10/10)
7. Gimp: Free photoshop (8/10)
8. Brave Browser: Browser with built in ad blocking (9/10)
9. Core Temp: Keep track of CPU temperature on all cores (10/10)
10. Discord: A chat service and voice software like Teamspeak (8/10)
11. Malwarebytes: A good antivirus software (8/10)
12. Cinabech20: A great way to test the thermals on a CPU by rendering images (9/10)
13. Prime95: A CPU stress tester, but you need to be careful not to go crazy with it (7/10)
This is all I can think of at the top of my head.