For simple lists and notes, I have a text file that I keep open as a generic dumping ground. Also, I use a program designed explicitly for making short notes that I use to keep track of some things. I step up to spreadsheets when I need to do some kind of calculations or want to produce a chart. (Even the calculations are nothing more than a moving average or something else simple.)

Once I start needing to do anything more complicated, I tend to step up to scripts written in bash or Python or PHP or whatever else I find handy at the time, which results in my not having many very complicated spreadsheets.