Heh, Eclipse is on the higher end of development not very worth it if you don't require things like autocomplete for your PHP, Java etc. It does not support PHP, JavaScript or CSS by default. You have to download plugins etc. Too troublesome if working on something small.
But with Eclipse, it is very scalable. There are many many plugins which you may install when you need it. I have been working with it on the past week. Still not very used to it though.
I guess
http://notepad-plus.sourceforge.net/ would be a very good editor comparable to those paid ones. It has really improved and have things like tabbing, code folding, syntax highlighting (duh!), session restore etc.
The another one would be
http://aptana.com/ which looks really nice but it is more on the client side or things and geared towards JavaScript side of things.
And this is a joker.
http://www.notepad.org/ 