I you dong get judged by how difficult the song is, but by the performance as a whole i d go: Cant stop- RHCP Its catchy,it has alot of energy so you can jump around, its famous.ish.., It looks cool when you play it, and you have some room to improvise.
Assuming that there is no additional performance component (e.g. vocals) involved; this is strictly bass playing, I would have to go the Jaco route. Portrait of Tracy is something that most folks would probably do, but not every setup can get those harmonics, and the song is kinda mellow. I would wanna be groovy and chopsy at the same time: Opus Pocus.
Probably Aeroplane by RHCP. Of course, this is all if we get a backing band. (or to band a back... however you view it )
If I've made it to national TV, it's because my chops are together enough to pull this off. Since they aren't at this moment up to it, I'll let my inspiration in the performance, Russel Blake, demonstrate my desire: Satin Doll If it's a Jaco theme night, he's got the goods here for it, although not nearly as inspired or inspiring as Russel is for me. iJazz - I mean it!
If you wanted to sing as well, that's your decision. Just like some American idols sing and some sing and play guitar.
RHCP Higher Ground, School Days and some other ad hoc silly slap put-together wannabe song you hear in the Guitar Center bass room every day.
Ramble On - just enough to show your chops and show off your gorgeous bass tone, but not so much there that you can't add to it and "make it your own" as the judges like to encourage contestants to do on American Idol. Although Simon might have told me I am old-fashioned. Or, I could take a cue from one of this season's contestants, and perform the bass line to the theme from "Facts of Life."