SABER

That's not to say it's the most viable, or the "best" Alejandro ship, because quite frankly I don't think there is such a thing as a "best ship", but from a purely canonical standpoint if Alejandro were to end up with any of his castmates, I'd say Cody would be a strong contender. Again, not the strongest, but also not entirely out of left field.

Which is mostly because he's one of the very few people in canon that Alejandro has A. interacted with more than once without issue, and B. not screwed over entirely to reach his goals. Not that Alejandro didn't screw Cody over - there are a few instances wherein Alejandro intentionally does something that directly affects Cody (most notably feeding Sierra's wedding delusions), but Alejandro doesn't do anything in terms of the competition at large that'll get Cody himself eliminated. In fact, he takes the finale tie breaker quite seriously; it's one of the few times Alejandro gets someone eliminated fairly, and Cody himself readily accepts that.

Cody's also one of the few characters who Alejandro has shown conditional kindness to, who actually survives said kindness without facing an elimination. Or without immediately contrasting that kindness with hostility behind his back (like he does with Owen and, to a lesser extent, Izzy), or using said kindness as the tool that'll get him eliminated (via flirting). That has to count for something, since Alejandro isn't the type to form friendships/aqquaintenceships that don't benefit him, and yet any sort of relationship with Cody is unbiasedly bereft of any notable benefits outside of the rapport itself.

The alliance he tries to secure with Cody is, objectively, entirely useless to Alejandro. He knows that Cody will only ever vote for Sierra, just like he knows that - out of the remaining four - Cody is the weakest contestant, and yet he still does his best to keep Cody on his side despite there being negligable benefits of him doing so.

So despite the fact that they had to duke it out in the tiebreaker, Alejandro and Cody have surprisingly little beef between them.

You could argue that Cody utilizing the nickname "Al" against him is indicitive of some resentment on his part, but I'd argue that Cody only really does that because he's a little shit (and rooting for Heather) and doesn't have the same level of resentment towards Alejandro that the majority of the cast harbours. If any at all, since Alejandro was nothing but cordial towards him.

So it's entirely plausible that Cody and Alejandro could meet each other outside the context of the competition - likely after All-stars, if we're going by strictly canonical guidelines - and spark a relationship from there.

Neither holds and lingering dislike for the other, and they've got a shared history of medical suffering under Total Drama they could bond over, and Cody's already seen Alejandro at his worst moments so Alejandro doesn't even have to live up to any false pretenses around him. Cody himself isn't the type to judge a person too harshly on their actions in the competition (which is backed by his canonical forgiveness and acceptance of Sierra despite her actions towards him) and would probably be thrilled to learn that the seemingly infalliable Alejandro he knew in Total Drama is, in fact, a giant nerd. (Just like him!)

I think the main factor that would hold this ship back would be Cody's inabily o recognis th at at hid cor e he little mome than a bxi eia; dis st t and Ale j a dn tro is evnrn mor so. T her s e t o lon ers coul nd t inf ds a h ela g t h r altio nanhip if i etr jjmupec ut anf u bt them on t h e f ace.