Oh... I dont know what to pick...
So i will pick 3 projects from my 3 stages of my dev "carrier"

1.Right after i discovered programing and learned how ,if, while and similar structures worked. The launguage was object pascal with delphi 2007
That was a "safe" with a stupidly complicated lock (text inputs, sliders, ect) it opened a secret folder in the end.

2. It was a embedded code for a Atmega8 AVR, Atmel studio, pure C but without memory managment (i didnt even know that it even existed)
It was a Pip boy knockoff, 16x2 display and a small keyboard connected to the arduino like board that i made on a proto board.
It wasnt that much of a pipboy, it was more of a showoff of atmega8 internal systems, (ADC, timers, interrupts and such)

3.DataLab, after helping my friend with his master thesis, (we meet on discord long story, i was in high school) i decided that mathlab is shit and i created a visual scripting enviroment, launguage C# .net 4 (in the latest version)
I remade the whole program from scrach 1 time, significantly improving everything (code reuse, better algorithms, data processing, code redability and edge cases) I have learned good practises from everywhere. I learned how to use git.

DataLab project looks just like LabViev (i didnt notice that it even existed...), it is frozen now because of my mental status but im planning on using it on my CV when i will be looking for jobs on holidays. There are many things that i can improve in that program but ... first i have to fix myself.