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I use Parallels 6 and VMware Fusion with my Boot Camp Partition.

I have to admit, I like Parallels more due to its speediness but I still like Fusion for its stability.
 
Bootcamp on laptop, parallels on work iMac. Really wanting to convert bootcamp to parallels...
 
My take

With all the problems from Parallels 6, I have to vote for vmware fusion as better as well as virtualbox because that one is free.

No, seriously though.. vmware is much more stable and fast enough for me.
 
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