In my opinion, Jarco > Starco.

Before I started watching the show I saw so much hatred for Jackie, that she was a slut and all these sultry looks she was giving Marco meant she was a massive whore and I guess 'Oh hey I wonder if she's like that all the time to all the boys', but then I started watching and... no, she literally only ever makes goo-goo eyes at Marco, that and apparently it's a crime to pierce your ears a lot.
Like damn, Starco shippers, you fucking venomous. I mean like, yeah, Star has a crush on Marco, and they're good friends, but Marco himself is all 'Nah man we're best friends and has snogged Jackie several times, she's canonically his girlfriend as said by Star, and we've not seen anything from Marco that would imply he fancies Star.
Yes while Star and Marco would be more 'fun' and magical and exciting, it's a case of Marco only has eyes for Jackie, he would prefer dating her and having the fun excitement of chaotic monster bashing and shit with a friend, as Star is.

Also fuck Pony Head, she's still a cunt.
Hekapoo is also a very silly name.