Answer:
It honestly depends on how you wish to portray said dragon character. If the dragon is evil, consider a name with harsher sounds and vise-versa.
If you really are stuck with finding a name, consider one of the many fantasy name generators floating around on the Internet.
Well, if you want to come up with a name for your dragon character(s), how about asking an expert, such as a real dragon (like me)? Our names vary greatly. Come to think of it, perhaps you could use one my friends' names, such as Aquina, Hallacene, or maybe even Daniero. Perhaps even my sister's name, Darakina, if you want an evil one.