There is a lot going into this
Sasuke (with Sharingan): All sharingan jutsu, plus his fire jutsu and Chidori +variants
Naruto (With Kyuubi): Rasengan, rasenshuriken, clone jutsu, sage jutsu, tbb, chakra arms (yes im countin that), assumed fire jutsu kurama has at his disposal.
Sasuke (No sharingan): Fire justsu (>wind jutsu), Chidori and variants, intelect.
Naruto (no kyuubi): Rasengan, rasenshuriken, clones, sage mode.
So, without their respective power ups, Naruto takes the gold.
But with power ups: still Naruto.
In way of POTENTIAL: Naruto has the potential of learning some serious, wind, fire, and water nature jutsu. Wind: Nature of his chakra, so easier to do. Fire: Kurama and learning some fire toad jutsu. Water: water toad jutsu. Along with other sage jutsu and whatnot
Sasuke: as far as the sharingan goes, he's at his highest level. new jutsu is just whatever he picks up, plus chidori variants.
So the final equation is: Potential + skills already acquired= power level.
Therefore with Naruto having the greater potential and skills acquired, naruto will be, and already is better than Sasuke.