You know who I always liked? Yuna.
Strip away all those fluffy cheesy JRPG bits of dialogue and leave just her intentions, she was a pretty strong female lead. On a mission of self-sacrifice while also keeping her dignity and upholding her moral convictions.
I dunno, others might disagree with me on that one.
Spoony kinda ruined Yuna for me by pointing out all her logic errors. Not so sure you can call a female lead strong when she lacks basic common sense about the way her own universe works. (Case in point: Failing to 'send' Seymour when he first drops, just electing to stand there and watch instead, only doing so far later with a more convoluted and less thought out plan.) Then again it's been ages since I played X myself so I'm not sure if he's spot on or just harping on a misinterpretation.
Even if Spoony's dead wrong X-2 kinda took a piss on the character anyway; which has a backlash effect on her X interpretation because you know canonically now she has that behavior within her.
If I remember rightly, the Guado in Guado Salam stopped Yuna before she could start the Sending and took Seymour's body away and hid it, the party are then chased out of Macalania Temple. It's also worth pointing out that the group are completely in shock about killing Seymour, a measter, and even after it I think Wakka says "What have we done...".
After the second battle with Seymour, I'm actually not sure what happens, I think it cuts to after the party have escaped Bevelle directly after the fight, but I think something similar to what happened in Macalania happened, as this is the moment that she becomes a wanted woman. I think one of the other measters at this point reveals that he is also Unsent, and Yuna shows every intention to send him
The third time you fight him, he actually falls down the mountain, so they dont have much of a choice but to go onward to Zanarkand.
After the last battle, Seymour has no one to save him since they are Inside Sin, and as soon as they beat him, Yuna immediately starts the Sending. So I dont think it was a fault in her logic at all, she clearly wanted to send him, she just never got the opportunity.
As for FFX-2, I can't defend that.
P.S: Spoony is a tool.