There are a couple of different naming conventions, and it all depends on who you work for and what the machines purpose is.
For a small/medium sized company, your production servers may all have a standard naming convetion like - - <#>
But their routers/firewalls may be named oddball names.
DNS servers on the otherhand are almost always NS1, NS2, NS3. That is pretty standard there. But again this will depend on the size of the company.
Basically the concept is, the larger amount of like machines that are deployed in the enterprise should have a standard naming convention that you can tell where and what they are.
The smaller amount of machines can be "colorfully" descriptive. So if you are an extremely large ISP with several 1000 routers. You wouldn't want to name all of them some weird names. They would have a standard.
Personnaly on my local lan, I like to make messed up names for personal wkstns. But production based servers follow a strict naming convention.
But again, if you are in a large company (1000+) users, making messed up names for the lan is probably not a good idea.
Which again supports my above notion about naming conventions for the the larger populos of machines.