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The only reason I use windows is for CasaXPS, Origin Pro, HiScore+, Labview. If I didn't have to do data analysis then I could live happily ever after as a mac-only. Thank goodness there is finally a mac-native version of Autocad - things were getting rough running it in a virtual machine on my mbp. Now that it's mac native, things are much smoother...
 
Quicken

Various software authoring tools for Windows

Various CAD software thats only available for Windows

Microsoft Word 97 (I believe!) for one document that won't port over to anything on the Mac.

WordPerfect 8 and Micrografx Designer for legacy documents.

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If it weren't for the switch to Intel and the availability of Windows VMs I could never have switched to a Mac. However 95% of my usage is Mac apps.
 
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