I'm still in the "tabs for indentation, spaces for alignment" camp. If you adhere to it, it makes your code look nice on any tab size.

Typing formulas in Excel

It's too bad spaces won, tabs is just correct I think, since one can configure the tabstop to use any indent size they would like. I'm quite tired of reading 2-space indent. Seems everything has moved this way now except python. I'm even seeing C with it, which is especially jarring. I think the languages that use braces for indentation particularly need 4. Python needs it least, and I can read Ruby because its blocks are delimited by words and it's bad style to write long methods