I have a ESXi 5.5 box. I've been using VMware for several years and it has been rock solid stable. However I've had a few crashes today. I am building lots of VMs and doing a lot of I/O with databases, and I've had four pink screens. Here's one as an example. Any ideas on how to troubleshoot? Should I just grab the latest build? I'm using 1331820.
Yes, you should update.
That is a bug which is fixed in VMware ESXi 5.5 Update 1.
I should probably also add that it's a good idea to keep your systems up to date to resolve a variety of bugs and security issues.
The quick fix for this if you can't update your ESXi host is to change the NIC adapter from e1000 (or e1000e) to the vmxnet3 driver. The default for Windows guests is the latter, but causes problems under load.
The top line of the stack trace indicates tat the fault occurs in E1000 driver. AFAIK that is the driver for Intel network cards.
I would start troubleshooting by changing the network adapter.