No answer on the google question, but you can choose plain text in text edit in the preferences menu. Yes it is annoying as hell, but it is there.

Oh, and I use TextPad or SubEthaEdit for my editing needs.
frozendice said:
Where is no special encoding, just plain text?!
You can make plain text the default in TextEdit in the preferences and you can always change any document to plain text by selecting Make Plain Text in the Format menu.

As for other text editors, I'd be hard pressed to make a recommendation as you seem to be having problems with TextEdit and other text editors (like BBEdit) tend to be more advanced. Recommending something else would most likely lead you to more frustration.