I don't really care for either since it's FE8, but Ephraim, Eirika was just naive and annoying, falling for that whole "OMG I needz teh stone to save myself", "Oh OK in that case here you go", "ha ha, I was lying n00b". At least Ephraim was willing to kill him rather then risk everything.
I hate un-confident characters, unless the really add to the story by being so, which is rather rare.