I can't say I remember the exact point that started me shipping them--I'm on season 3 and don't seem to do much rewatching of this show--but there's this one part where Moira and Walter (from Arrow are about to meet for dinner, and it just made me remember just how much I ship them. I mean, Walter wasn't even onscreen, but Moira and Thea both looked so happy and expectant and--well, I found myself sitting there grinning, so...keep going, Arrow. You're doing something right.

(Also, Oliver and Felicity, aaaah. They keep getting cuter and cuter with every episode, and I'm talking about a vigilante/superhero and an IT girl, here. And no, I don't really remember when I started shipping them, either, though by now there are so many lovely shippy moments that you can take your pick.)

~DF

Homestuck:
No spoilers:
I started shipping Dave and Jade during one of their pesterlogs, when Jade was trying to make a reference to Dave's webcomic and she got it wrong. She realized she got it wrong, but Dave said, "no its alright. reference secured" and I started shipping them like Chinese goods to the U.S.

Homestuck:
SPOILERS AHEAD
There were actually two moments for this couple. During the [S] John: Reunite with your loving wife and daughter flash, while Karkat is watching John, Terezi bolts up, shoves him aside, and starts pointing at his screen and presumably giggling. The look of annoyance on his face is glorious, but more on that presently.

The second one is after Terezi watches a doomed Dave die. She's almost crying and Karkat comes up and looks at her from way in her bubble. Then he goes to poke her.

These are cute enough by themselves, but not necessarily indicative of romance. That's just how Terezi behaves around everyone, and Karkat is later seen to be poking Sollux in a similar manner. What got me shipping them is the fact that they behave almost exactly like my brother and sister-in-law... whose favorite colors are red and teal, respectively... which is weird...

But think of how awesome it is that I get to ship my brother and sister-in-law as fictional characters, and aliens, no less!

Doctor Who:
SPOILERS AHEAD
Amy and Rory. I have to admit, for the entirety of Series Five and the beginning of Series Six, I though Amy was just plain annoying, and might possibly have had an unspoken rule to sleep her way around the universe. Or maybe just the TARDIS. Then, The Curse of the Black Spot happened. The interactions between Amy and Rory were so amazing during that episode! I think, though, that the part that especially got to me was when Amy was trying to convince the Siren that she was legally responsible for Rory and the short bit where Rory was teaching Amy to do CPR. Now I just think they're really cute together and I love them together.

That's actually pretty much my shipping life. I just don't ship that much.

Spoilers will be marked ((like so)). Read at your own discretion.

I don't tend to ship characters too often. I started shipping Makoharu harder after I watched Episode 6 of Free! ((you know, the one where Haruka gets that close to giving Makoto mouth-to-mouth?)). It just made sense; the show was already teasing that pairing anyway.

I also started shipping Lyra/Silver when I got SoulSilver back in freshman year. Two reasons for that: first, Silver looks prettier in that game than he did in GSC, so it was easy for me to fangirl over him; second, I actually beat Lance in SoulSilver and thus got to witness more of his character development ((especially at the double battle with him against Lance and Clair in Dragon's Den))

To answer your actual question, though, I remember really wanting to ship Sherlock/Irene for a while the first time I watched "A Scandal in Belgravia" (or was that Sherlock/Molly? I can't remember, the episode kinda sorta teased both.) I guess it was the way they interacted; neither side willing to give ground (at first), both parties on each others' intellectual level...yeah.

I mean, I was reading a lot of the ship-tease in Star Trek:TNG, but I wasn't interested in that sort of stuff.

There's Alphonse Elric and Martel, with full knowledge that it wouldn't have worked out, especially as anything sexual.

I have feelings against one popular pairing, but I wasn't watching The Last Airbender in any specific order and pretty much got stuck on the official couples.

Well, I was recently watching Doctor Who, and in specific the Season 2 episode The Idiot's Lantern. And the ONE MOMENT when he realises what they did to Rose (took her face and dumped her in the street) and his Tranquil Rage...as well as their reunion at the end... well, I'm now a 10Rose shipper. In a simular vein, Rose being so mad/terrified for him in Fear Her really got to me.

And the Amy/Rory ship only really kicked in for me in The Angels Take Manhattan when Amy decided to jump off the roof with Rory even though there was a tiny chne she might survive. Plus she ignored the Doctor just so she coul be with her husband.
The one line that really got me was this-
"We're changing the future. It's called 'marriage'."

Plus-
"Raggedy Man- GOODBYE!"

definitely Act IV scene iii for Brutus and Cassius. Didn't help that the first production I saw of them had them kissing in it.

But going back to my other ships? Imma have to go with the 'because you are my friend' scene for Kirk and Spock, because even though I would love to rip the scripts of the Reboot to pieces, I have to admit that particular bit got me going OH YOU TWO I SHIP IT.

And for BBC Sherlock, I definitely shipped John and Sherlock by the end of PINK. Whoops. Probably the instant when John looks at Sherlock and is all 'oh god yes' to seeing more crime scenes. The acting is phenomenal in that bit, the tension extremely palpable. And I'm pretty sure most people don't say 'oh god yes' in the tone Martin Freeman used in that scene when they're going to go see a crime scene with someone they've barely just met.

...but I found that Kellam (a knight in an oversized suit of armour that everyone seems to forget) and Maribelle (a snobbish upper-class lady that is an expert medic/combat mage) from Fire Emblem worked vey well with each other. Each is the polar opposite of the other and they just play off each other so well, IMO.

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