ME's entire sequence from Virmire to Ilos to the Citadel is pitch perfect, especially Ilos and the Citadel. It has a level of tightness that's really lacking in DA. But on the other hand, DA is about three times as long as ME. In terms of overall content, DA wins. The overall depth of the universe, the overall depth of the characters, better world building, less cookie-cutter sidequest bases, more lore, etc. ME's pacing, though, makes the endgame more memorable than DA's.
Plus DA's combat kind of sucks. :lol
Overall, I would say both of them are 8 or 9s. DA has maybe a SLIGHT edge based on game content, but not that much. 5 is ridiculous, even if you take it to mean "average". If only all those "average" games out there were as good as DA.
That said, I fully expect DA's sequel to improve on DA's combat (just like ME2's combat seems to be far more advanced than ME1), and for ME2 to improve on the dialogue and character aspect, as Bioware keeps stressing that they have, so.
Edit: I didn't enjoy Fable 2 nearly as much as DA, even though I liked it enough to play it twice. Personal taste, I suppose.