The only ones I liked are the Costa Del Sol and maybe getting all the summons.
Trophies/acheivements should not be about doing annoying things like changing a character's name or over-the-top challenges like beating the WEAPONs or mastering all materia.
I agree about changing a characters name not being an achievement, but I don't see anything wrong with the Weapons one, or the Mastering Materia one. Stuff like that or breeding golden chocobos ARE achievements. They take work to do.
There should be an achievement for being selected by Don Corneo.
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"One of these days, I'm gonna find a loophole my friend." - Man in Black