Cloud and Tifa (SOME SPOILERS)
Final Fantasy VII is honestly one of my favourite games (no, stories) of all time, no more so than for the engaging characters it presents, and like any great medium it really has you caring for the characters and the well-developed relationships between them help you care for the characters even more (aren't the writers behind the FF franchise just fantastic at this? lol)
I felt this the most with the relationship between Cloud and Tifa. To be honest, I think there's hardly a greater example of friendship, loyalty and dedication in fiction than Tifa's relationship with Cloud. I'm actually somewhat shocked to realise that I could be so touched by a friendship presented in a video game of all mediums! Just by seeing how Tifa interacts with Cloud in the story, you know there's nothing she wouldn't do for him, and as awkward as Cloud is with his feelings, you can tell he feels the same way. They started off as hardly more than childhood acquaintances but as adults they get extremely close through adversity and common experiences (i.e. the events of FFVII) and as a result, an immensely strong bond of trust grows between them that they share with no-one else. *sniff*
Of course, the game leaves it up to the player whether or not this relationship is romantically based, but I found myself not minding at all whether it was romantic or not, as long as that bond of deep trust and unconditional love always stays between them. Out of team "Clerith" and team "Cloti", I lean more toward Cloti - only because Cloud is really shown to have a much more meaningful and personal relationship with Tifa than he has with Aerith, as special as his relationship with Aerith undeniably was.
The part of the game's story that showed the true depths of this bond between them is, no doubt, the part near the end where Cloud is affected with Mako poisoning and is pretty much a vegetable. Tifa, by choosing to stay with Cloud and look after him (even when there was little hope he'd recover) rather than continue with the very important mission at hand, this shows more than anything else that Cloud means everything to her and there's nothing she wants more than his well-being. I found it truly touching that anyone could be that loyal to someone, in fiction or out of it - as it's like Cloud's literally the centre of her universe (but in a very good way).
And as for the infamous "Under the Highwind" Scene: Some think something sexual happened between them and some don't, but my money's on this: they shared some very intimate feelings with each other, and ended up sharing some kisses (in the heat of the moment kind of thing), but they didn't go all the way. I don't know, I just always imagined they'd be a bit too tired for it (even if they wanted it) after all they'd been through that day lol. But of course that's just my bet ^^
I hope I got the point across OK - and I really hope that other FFVII fans here got the same impression. Please excuse the long post! I'd really like to know what you think.