Personally, it depends on what I'm working on. If I'm doing something in Java or for Android, eclipse is a given. If it's something in the .NET languages, visual studio. If it's plain html or an interpreted language, I'll use Notepad++
EDIT: FWIW, I do .NET stuff for a living so the majority of my time is spent in visual studio and SQL Server for writing SQL queries/stored procs/etc., but I do toy around with the other ones here and there.