The difficult part is virtualization solutions aren't all optimal out of the box, so any evalution of them by someone new to a given product might be skewed.
I'd look at what the big names are, especially in paid versions as they have their business on the line, and check youtube or blogs for performance tweaks or maximizing performance, and see what those who use it day in and day out have found. There aren't any real benchhmark sites or articles I'd recommend, as it can be hard to distinguish unbiased reporting from advertising.
Personally, I would give the VMware products a trial (most have 60 day unlimited use options), but I'm also biased having been a VMware VCP5. Anecdotally, their performance (when set up properly) was better than when I ran VirtualBox or Xen.
Make sure all virtualization extension options are enabled in your BIOS, first off. Second, save some cores and RAM for your host machine. More cores is not always better when it comes to VMs, but this applies more to multiple VMs on a machine and CPU scheduling issues. Third, turn off any power saving features in the host software or guest VM. Things like CPU C states can be a silent performance killer. Fourth, make use of whatever metrics or utilities the software provides to see at the host and guest levels where the bottlenecks are. The guest may think it's waiting on CPU while the host is busy paging memory blocks on disk.