The default virtual network adapter emulated in a virtual machine is either an AMD PCnet32 device (vlance), an Intel E1000 device (E1000), or an Intel E1000e device (E1000e). VMware also offers the VMXNET family of paravirtualized network adapters, however, that provide better performance than these default adapters and
should be used for optimal performance within any guest operating system for which they are available. (p. 47)
For a majority of general purpose applications, and for moderately latency-sensitive applications, the VMXNET3 virtual network adapter, left at its default settings, will provide the best performance. (p. 40) — vSphere 5.5 Performance Best Practices
We have had some reports of people having troubles with the E1000 adapters in vSphere 5.5, especially the E1000E (most report the latter), leading to the dreaded Purple Screen of Death (PSOD), as mentioned in VMware KB 2059053. Also see VMware Community Thread 459220.
This is one of the reasons typically that VMware recommends using the E1000 only as a startup or default adapter, not as the ideal one; VMXNET3 is typically recommended as a best practice.
Unfortunately, a lot of VMware admins (unintentionally) leave their VMs with the E1000 by default, instead of changing them to VMXNET3, either after deployment, or even in their virtual machines templates.