which anime do tu think i should buy?

Well, on Amazon, Skip Beat is about $50 while Ouran is on sale for $35, and The blu-ray version is on sale for $25. However, it depends on which one tu want the most, so we can't choose that for you. I would recommend buying your favorito! if tu have the money. Otherwise buy the cheaper one for now and save up for the other. I'm assuming you've seen them both. If tu haven't though then just look at the genres and summary of both shows and try to figure out witch mostrar is más suited to your taste.