I have and use both Parallels and VMWare Fusion on a Macbook Pro. Personally I prefer VMWare because I've run into less problems managing VMs with Fusion than I have with Parallels. In my experience Parallels updates are more likely to break compatibility with old VMs. I don't really use the "Linked Clones" snapshot feature of Parallels so VMWare's Snapshots work just fine for me too. I was pretty sure Parallels use to cost much more than VMWare for a single seat but a quick check shows that they're both about $80USD at the moment.