Meh, I want Spectacular. Calling it 'Amazing' means people will assume it'll be true to the first few decades of that comic. If they call it Ultimate people will think it'll be based on that version from the comics.
I think it's gonna just take stuff from all the titles. I've never read Spectacular, but I assumed it was a kinda happy medium between Amazing and Ultimate, which is what I think the film would be like too.
I think Astonishing sounds pretty good too, since that is the UK's version of Amazing, I THINK, I'm not completely certain. And it sounds kinda different.
But yeah, I would think they should go with Spectacular.