Windows open maximized by default?
Somehow most other software I use opens up maximized anyway, possibly because I use ShiftIt and Ctrl-Alt-Cmd M a lot (and most software seems to remember the previously used window size). The only thing I use a lot that didn't open maximimized was iTerm2.
You can get iTerm2 to open in a maximized window by going to Preferences -> Profiles -> Window and setting a high number of Columns and Rows.
I know this is not a completely satisfying answer to the question but it seems there is none on OS X.