XMind 

XMind is a editor that has a few interesting features (such as Gantt charts) and a nice (if somewhat infuriatingly “social”) map sharing site associated with it.

Its only serious drawback is that it compounds the fact that it runs (or rather, crawls) under with an Eclipse-like look (which I hate), but it opens files and looks vastly better than on a , so it has effectively replaced it for handling those as far as I’m concerned.