well...concerning Sheryl gift to Alto contrast to Ranka's, Alto has only opened up as person more to Sheryl than to Ranka, Alto has never told Ranka his desired to fly free in an atmosphere and his hate to Frontier for that, he also never mentioned his Kabuki background to her, remember the Zero episode when Ranka finds out about it from the directors and she asks if Sheryl knew about and she says of course she did and Luca just says that he mentioned something about it, and Ranka gets angry and leaves 'cause Alto seems to confide more in Sheryl than her
so, as a fair nod to Ranka, she really doesn't Alto really well to get her what he 'really' wants, unlike Sheryl, although, I'm sure if she knew, considering she's just a kid she couldn't have done any better
and I don't think Alto's being selfish, I mean, it's your bday and you're getting 3 options
1. To go back to your miserable life with your dad
2. Fulfilling a life long dream
3. Eat a pack of small airliner (which he hates airliner, remember his comment of episode 1), cookies
Sheryl hit a home run
either way, I still want Alto to end up with Sheryl, aside from my girlfriend who wants Alto to end up with Ranka, hahaha