Aside from having a fabulous wardrobe?

What makes me happy is how our actions have consequences later on, not all for the positive. You naively trusted Laurentius? Ooops, that jerk stabbed you in the back later on. You inspired Edda to brave on with adventuring despite the loss of her fiance? Oops, she got involved with a cult and is into necromancy now. You fought Diabolos in Lost City of Amdapor? Ooops, now he's gone and liberated the Queen from the void ark.

That is classic Final Fantasy storytelling and I love it. Good deeds can have unintended consequences.

I also like the fact that if you didn't want to be the Warrior of Light, you could stop doing the MSQ after level 15 and just make a living as a merchant or farmer. You'd miss out on 90% of the game, but that option is totally a viable one.