Hi, Seth1028, here. I know this wiki is probably saturated with irresolute "Creddie vs. Seddie" conflicts, but I ask you to please indulge me as I'm new. I'll try to support my claims using evidence from the show. I can say that the Seddie ship will win, if you want to use such terminology. Even though, I'm a seddie-supporter, I'm am not against creddie in any way. I just believe that the show has fleeced any remaining potential for a Carly/Freddie relationship. iCarly has spent a lot time, not just developing Freddie and Sam as individual characters, but also the dynamic shared by these two. Unfortunately, neither Carly's character, nor her relationships with Freddie and Sam has been afforded such attention. I argue that the entirety of Season 4 has been focused on Freddie and Sam's relationship. First, being that in the episode iGet Pranky, Freddie, for the first time, explicitly sides with Sam against Carly, which had previously been uncharacteristic of him. Also, throughout the entire episode, Sam and Freddie work together (without Carly) to pull off a prank. This showed that both Sam and Freddie could be congenial without Carly acting as peacemaker or being a source of conflict. And of course, their relationship reached a climax in iOMG! where Sam is the one who initiates a quite passionate kiss with Freddie.
We like to nitpick at every little action made by Carly, Sam, and Freddie, and "chalk it up" to the Seddie or Creddie column. But we must go beyond Carly speaking to Freddie in a "flirty" tone, or Sam making room on the couch for Freddie. They're all friends, so it's no surprise that they get along most times. The only official Creddie episode is iSaved Your Life (and maybe iOpen a Restaurant). Seddie has recieved about five episodes (maybe six) dedicated to Sam and Freddie's romance. And as the final season is ending, a lot of the nuance and undertones of the plot are geared towards Seddie. Case in point: in iGet Banned it was strongly hinted that Sam sabotaged Freddy and Gibby's front, because she was bothered by the attention they received (from girls.)
I like Carly's character: she's nice; she's funny and quirky; and she's very high-minded. I do think that she would make an awesome girlfriend to Freddie. However, the show has spent little time developing any substantial engagement between these two characters. I ask anyone willing to disprove that point. We also must remember that we're dealing with the relationships of teens, so anything long-term is ambiguous at best. I support Seddie because Sam and Freddie's characters supplement each other. Freddie is the stability that Sam needs in her often unpredictable and uncoordinated lifestyle. Sam is the disorder that Freddie needs in his often arranged and regulated lifestyle (due Mrs. Benson of Course,) which I can say with confidence is something that he does not receive from Carly (quite the opposite actually.) I think Dan Schneider purposedly fiddled with these two character archetypes in order to demonstrate how such dynamic personalities can gravitate towards one another and intergrate.
So why do I think of "Seddie" as bittersweet? Mostly because iCarly isn't a teen-drama, it's primarly a pre-teen comedy show. I bet many "Seddiers" have wondered why Freddie and Sam broke up, given that they do have a lot of things in common (food, MMA fighting, technology, crazy mothers, talents outside of academics, intuition, and interestingly enough, they were both scouts.) I think it's because the Seddie arc strayed from the comedic tone for which the show is known. Also, Sam is moving on to her own show, so the possibility of a long term Seddie is compromised as I'm sure she'll have other love interests in Sam & Cat. I know a lot of people like to vicariously live out their own romantic fantasies through empathetic characters like Sam and Freddie, but I think it's important to come to terms with what is, and not what [could/should] be. If anything, the final Seddie moment is likely to be very poignant and, again, bittersweet. I'm probably one of the few Seddiers who hope that Sam and Freddie don't get back together in the end, but wishes to see a very purposeful expression of closure between two people who--to borrow Freddie's words--have been at each others throats for so many years.