Mine are usually spur of the moment names.
Querinox was my first wyrm and of course the first thing I saw when trying to register was something about not having an already current name. Being the noob that I was, I figured this game had been going on forever and in Drag Cave fashion, I made a rather unlikely to be duplicated name. Of course right after I named her, I found the part of the wiki where all the wyrms were named. XD
Raven: I picked her up without the slightest idea of her gender, so I needed a gender neutral name. I was kinda surprised this name wasn't snatched up already, so I registered it as soon as I could.

Denver: Well, I had just come from visiting my parent's house who seem to always be 'from Denver' (incorrectly no matter how many times I correct it) according to many of my friends and my boyfrined's mother. It seemed to be a popular enough male's name, so Denver it was.
Ginger: I needed a 'playful' name for this adorable mountain wyrm, but was coming up empty for a name. I also was getting hungry and ended up in a food-y mood so I named her Ginger for lack of a better name. It sounded playful enough to me.