Question for software developers: how do you organize your To Do list at work?

I'm asking because I'm wondering if there's a more efficient way for me to handle my notes at work. Currently I just use a txt file in Notepad++. I use this file to track all of the stuff I have to do, such as tasks for stories I'm working on, next steps for projects, discussions I need to follow up on, questions and ideas I want to bring up, etc. The way I organize the document works pretty well for me, but I'm just curious how other people do it.