SG-1 is the main "False-Gods" show, but in some cases it's a bit of a grey area - did the gu'auld start the whole god thing, or did they impersonate deities that the ancient religions had? Yu never even impersonated a god, but was an emperor.
SG-1 made it pretty clear on a number of occasions that the Goa'uld copied existing beliefs from Earth. Although from the chronology, it's possible that Ra the Goa'uld was the source of belief in Ra the deity, which is presumably what the makers of the original movie intended.
				
), one also needs to consider, beyond questions of characterization, how difficult it is to accurately represent an entity that ought to transcend our comprehension to the extent that conventional ideas about space, time, existence and morality are slippery if not entirely inapplicable. Think of the wormhole aliens: their conceit was existing eternally outside of time (a quality that's been used on Abramic deities as well), and just that one feature proved extremely challenging to both relate to linear characters (and the linear audience), where existing at all points in time is so outside our experience that it is difficult to phantom their motivations and the causality (if any) of the actions they undertake. Now imagine a deity with several more universal qualities, some of them logically self-contradictory, and try to represent that onscreen.