Neither one of them is going to take this team anywhere with out the other. (Plus a couple other players too.)
2004 Pistons had Ben Wallace at his defensive prime. He was a force, just not on offense. 2008 Lakers had Pau Gasol and Bynum. I would say Pau was killing it all season last year. Really the only teams that have won without a quality inside player were the 89-90 Pistons and Jordan's Bulls with Rodman (Horace Grant was pretty damn good the first three titles).
"Dominant" implies HOF caliber. Gasol was good last year, but 18.9/9.6 is not dominant. Wallace was dominant defensively, but all the other centers you listed were threats on both sides of the court. Now you've changed the argument from "dominant" to "quality"? OK...
I'm surprised to see the polling going 75% in favor of Oden at this point. Oden has had a number of very encouraging performances - but Roy has had two seasons worth of All-Star games. It's true, he hasn't been as dominant so far this season, but to say he's not the Blazers' most important player - and that Oden is - is premature to put it mildly. Roy is still the on-court brains, the clutch performer, the tone-setter, and the attitude of Portland Trail Blazers. Without Roy, the Blazers are a .500 team at best. Without Oden, we've seen what the Blazers are (last season, when Oden was of minimal importance): they're still a playoff team in the West. That said, if Oden continues to progress, he has the potential to turn a playoff team into a championship team. But it's potential, still, at this point.