Norse. I'm oddly attracted to that mythos in particular, especially the tales surrounding the Aesir and their realm of Asgard. It's fascinating stuff, even more so when the "gods" can also suffer the fate of mortality.
Greek. I loved how the Gods and Goddesses were so imperfect, and angry. Plus, mt. olympus just creates this beautiful visual of the worlds prettiest people living on beautiful, soft clouds... I would love for that to exist.
I'm surprised Christian mythology is not an option, it seems to be pretty popular. I do hope it's not because anyone thinks that it's already a reality, though I know, unfortunately, that many people do.
The god Loki who, like Prometheous, was inclined to shed light upon those who did not have it.( the light being knowledge and fire for comfort) In doing so they both incurred the wrath of thier peers, yet a grudging sort of respect as well. The runes that were created back then are almost perfect in match to the 25 cartouche from Egypt. This syncronisity has great appeal for me.
It's far too hard to choose between Japanese, Egpytian, and Norse. >< Perhaps a weird mesh of the 3? I like how the gods are interrelated and explains just about everything there is on Earth and they are powerful but they still have weaknesses/personalities.