The reason I like tabs is because of metainformation - one tab = one level of indentation. I use tabs only at the beginning of the line and only to indent. If I need to vertically align, say, the fat commas in a hash assignment, I use spaces; even if for some reason I wanted to right-align said hash keys I would indent them with tabs then add spaces in front of the keys.

That way, so long as you don't vertically align things on lines across different levels of indentation (and if you want to do that, something is probably wrong), everything will always line up regardless of the reader's tabwidth setting.

(See Re: download progress with gtk for an example of how I indent.)

Makeshifts last the longest.