If you play a human then I guess all the planets would be named from a human perspective. So what would we name them? I guess we would keep using our already established naming convention of naming them after Gods. I'm sure across all of our cultures you could find 500 names of gods great and small. This could even help give some flavor text for each planet, with a little about the god and why it is relevant to the planet. The cerberus system may be a system with three suns, and the planet Posiedon may be a water planet?

Greece has just under 100 to get you started:
http://en.wikipedia.org/wiki/Family_tree_of_the_Greek_gods

Then there is Roman, though obviuosly some of them are already in use:

http://en.wikipedia.org/wiki/List_of_Roman_deities

Then for some less obvious choices there are other cultures like Maori and Mayan who have some great names:

http://en.wikipedia.org/wiki/Family_tree_of_the_M%C4%81ori_gods

http://en.wikipedia.org/wiki/List_of_Maya_gods_and_supernatural_beings