Honestly, I'm tired of most RPGs (most notably FFVII and VIII) and many new platform 3rd person shooters/explorers, having the whiny, emo, misanthrope heroes. That isn't to say that I like Grecian superman-type heroes any better.
A hero should remain somewhat grounded, and respond emotionally in a logical meaning. On the other hand, the hero should have enough self-confidence and charisma that people will do the crazy things she or he asks people to do. This is especially true of RPGs, where the hero is usually asking of the allies to die for some cause. Why would anyone actually want to follow Squall, when even Squall didn't want to follow Squall, he was mentally, emotionally, and politically weak. Then again, considering Cid wasn't that put together either, I guess the Garden was used to bad leadership.
Cloud, on the other hand, seems to go from either way too stoic, to way too emotional. Considering he knew Aerith for a grand total of maybe a month, there really wasn't that much of an emotional connection. Before you say "love at first sight!" you need to disillusion yourself of such myths. More than likely, it was certainly a healthy bit of lust at first sight. Then there's the whole breakdown when he finds out that his ego stroking has been all a lie.
Honestly, silent protagonists, while usually seeming a bit unemotional, tend to be the least annoying.