Got seriously annoyed today by Open Office.
I know it's free, but I have a rather simple point to make:
If you don't have development time to do a feature properly do not include the god damned feature.
I am talking principally about formatting of visual and text elements. They should not change between saves. They should not autocorrect to standards buried inside the source code.
It is a hundred times better to present a handful of features done well, and let the user improvise using them, than to have thousands, with unpredictable and undocumented interactions.
The example I'd use in the converse is Paint.NET, which with one notable exception (shading) is trouble free. It isn't photoshop, but it's free and it works.