I recommend the Dell Precision Workstation product line. The next business day on-site repair/replacement is fantastic. Also, you get access to "real" tech support, not just someone reading from a script. That is also extremely helpful.
For example, when something went wrong, I was able to call Precision support and tell them what I had done to diagnose the problem. After hearing that, they immediately said, "yes, if you have done that, it's definitely the XXXXX that isn't working. We'll get someone out there tomorrow with a replacement." No formatting your drive, no nonsense tests from someone reading from a script.
You can likely get a better home-made system for price/performance, but Dell Precision Workstations are our system of choice.
That said, we have upgraded the RAM and video cards in them, but they have performed very well for us. 16GB of RAM is plenty for the 3ds max files we use. For some, perhaps 16GB would be insufficient. You'll know your 3ds max scenes better than we will.