Lets see: a scavenger species that has no real technological advantage in this situation whatsoever, or a species that, to quote Weir, "Defeated the Ancients!" (Who, in and of themselves, were the source of the tech used by the Goa'uld.) Wraith, unfortunately, take this one by weight of numbers, based on known feats alone. (Please provide contradictory evidence, if you can. I honestly feel like the Goa'uld were the better villains, just not as powerful)

The Wraith... let's be real. Have you seen the guns on those ships. Plus even human they are serious opponents in a fist fight. The Goa'uld are worms.

Well, if the Goa’uld could take the Wraith as hosts they might actually stand a fighting chance.

Wraiths.