There's been plenty of valid criticism directed at Guy here at news.yc (for example, he gives startup advice but hasn't had a successful startup of his own), but I really don't think he has a large ego. In fact, what I like most about his presentations, interviews, and moderatorships is that he's always poking fun at himself. He always mentions his stupid mistakes in a way that's funny and endearing.

I've also emailed him personally a couple times and he answered the email himself, which is not a characteristic of someone with a delusional sense of his own importance.

He's also quite up front about having no successful startup, at least in two interviews I've listened to (he brings it up without being asked directly).