Quistis: I guess I was right. You and Seifer are in a class of your own. You
both have amazing strength and potential.
Really? If Quistis actually dislikes Seifer, her answer would be more biased. Therefore, she lies...

Also, it's proven true that Quistis likes Squall. She basically asked him why didn't he dance with him at the Party:

Quistis: So you'll dance with someone you don't even know, but you can't stand
being around me?

Quistis: I
wonder what's to become of me? I've come to give you an order.
-

Quistis: What's going to happen to Seifer?
Since when do you care about Seifer?

Quistis: I don't have any good memories of him (Seifer). I've seen some
troubled children, but he was beyond troubled. Well, he wasn't really a
bad guy.
Oh, really? Trying to find an excuse so that you wouldn't be sad about Seifer dying? Not to mention you said this infront of Squall...

Maybe Squall and Seifer were fighting over Quistis in the beginning?
Would that also explain why Rinoa and Seifer broke up, since Seifer was cheating on her for Quistis??