WinDirStat or DiskInventoryX replacement

Looking for something like WinDirStat
With Duplicate scanning removal the most important function..

I used DiskInventoryX in the past but it now just crashes.
Preferably at the cost of the above. ie: Free. :)

thanks
Ian

ps. also relates to this thread: http://forums.macrumors.com/showthread.php?t=1605057