Squall- For his physical damage (mine had 255 str since about middle of disk 1, killed Ifrit with 1 trigger-hit (with punishment at that point), and ~8000 damage vs. X-ATM092 (beat him 8 or so times and got Mag+(bonus) with Siren there)).

Rinoa- Angel Wing in very powerful (ex. meteor does about 7000-8000/hit), and angelo sometimes revives/recovers/counters and has invincible moon (and I should also mention Wishing Star!)

Selphie- Full Cure, Wall, Rapture, THE END (once she used it on lvl. 10!), AND she gets 255% hit with Strange Vision (which is quite simple to get and proves very useful vs. cactuars)