Mine is actually quite complicated, but does follow a certain logic:

Server/desktop machines acquired used/old are named after dinosaurs
Server/desktop machines acquired new are named after lizards
Mobile(handheld/laptops) systems acquired used/old are named after ancient flying lizards
New laptops and such are named after modern, extant birds of prey.

Which gives me machines like:
gecko, iguana, thornydevil and komodo as well as ones like hadrosaur, dimorphodon, dromaeosaur, kestrel and merlin.