I can't believe this one wasn't brought up.
I use Looney Tunes at work.
Two reasons, 1.) There are a lot more than I will probably have servers and 2.) Each name somehow relates to something so I can easily remember what one to go to.
Example...
Daffy - My Workstation

Bosko - The old enterprise software server
Porky - One of the database servers
Foghorn / Leghorn - Two test servers
etc. etc.
I also use Bugs, Marvin, Elmer, and Sylvester; Tweety and Roadrunner are in the works.
(Didn't want to give away all of the layout of course

)