Seifer x Zell is a pretty popular pairing in the Final Fantasy yaoi realm although I must admit it is quite a random pair since they don't have much of a yaoi innuendo in the game. However, the combination of their very different personalities makes it feel like something sweet and adorable would come out of their story.
We've had so many brother x brother, twin x twin and all that but never any uncle x nephew!! And of all things, the uncle is happily married!! Imagine the drama!!! LOL!!! Two sweet people, separated by so many different taboos and reasons... I believe nothing more needs to be said cos' I expect that yaoi fans have the most creative minds of all humans. LOL!
Later after Vincent defeated Vice and Vice regained some control over himself, Nero reappeared in a shadowy form (his spirit??) and talked to Vice, even giving him a passionate hug and asked that they 'become one' so that no one will ever separate them again. ZOMFGWTFBBQ!!!! *DIES* Vice smiled softly and agreed, and then Nero's spirit merged himself with Vice. That's the last you'll see of Nero, but OMG..... I can't even describe how intoxicated I was!! If you ask me, these two are THE #1 brotherly-pair with the MOST official yaoi-backing proof. O_O!!!! KYAAAAA!!!
I must say, SenRu (SendouXRukawa) has gotta be my top 5 favorite yaoi pairings of all time. Though different people have different ideas on how SenRu is probably like, the way I see it, it's mostly fluffy, innocent as well as angsty, which is my ultimate favorite combination. XD!!! In my opinion, Rukawa is stubborn (potentially slightly childish), practically an introvert and hiding his emotions and thoughts all to himself, but he's not afraid to admit what he really wants to himself, and to go for it in his own vague way. On the other hand, Sendou is friendly, outgoing and sociable, the kind of guy who's popular among all, but who is rather shy towards his special someone. I gotta admit that that I've been influenced by the best Slam Dunk doujinshi in the world - Deep Purple, but I sure as hell agree that that's the kind of outcome we would get from a combination of these two sweet boys. I love them so much I could cry. In fact, I probably have.
These two probably form yaoi world's most 'unpredictably evil' pair. Aizen, the preferred seme, is simply power hungry and is the calm and cool type of badass and knows how to manipulate others to his liking. Gin, my personal favorite from this series, is this very badass's trusted righthand man, or "irreplacable vice captain" or so Aizen once called him. He is equally unpredictable, or rather even more so, considering his motives and objectives are still entirely unknown even to this day.
For that reason, it's hard to find backing/evidence/reason as to why these two make a great couple. For those who've seen even JUST 2 episodes of Trinity Blood and would love an innocent romance yaoi fanfic, feel free to check this out - Mechanics of Love. I wrote it over 2 years ago (even included graphics!) and I STILL love it despite its simplicity. ^__^ Perhaps after reading it, you'll know why I love this pairing so much.