Just a few things that I've been brewing over:
1.) All throughout middle school, high school, and college, Peter's best friends were always girls, and he was always That One Guy at events like "Take Back the Night" rallies.
2.) Peter falls in love at least once a year, and he always manages to sabotage it. It isn't that he's insincere - he just wouldn't know what to do with a functional relationship.
3.) He went through a phase where he was very loudly bisexual and brought it up all the time, especially when his dad was around.
4.) Peter is bipolar, and so was Arthur (I don't know what Angela was on about with "major depressive disorder"). He has had minor episodes of mania from adolescence onward. He had one particularly bad episode in college where he asked Nathan to kill him to prevent him from destroying the world. Nathan had him discretely treated at a private clinic. Neither of them ever told Angela or Arthur. Peter doesn't remember much of the incident; he thinks Nathan overreacted, and that there isn't anything wrong with him.
1.) I think this is pretty much canon: Mohinder's first reaction when angry is to throw something. He has beaned many people by accident because of this. He's never had the occasion to find out, but he would make an excellent basketball player.
2.) Mohinder has a lot of trouble with emotional intimacy, and he can be downright mean to whoever he's in a relationship with. He fights very dirty.
3.) He's had sex with both men and women, but doesn't really see the need to classify himself. He's also a very bossy bottom.
1.) Sylar is honestly puzzled as to why Mohinder is so angry with him. I mean, clearly anyone with half a brain can see that Chandra horribly betrayed him and had it coming, and besides, Mohinder and his dad never got along anyway, so what's the big deal? He's sure that Mohinder will come around eventually - he's just a little stubborn, is all.
2.) When Sylar was at Zane's house waiting for Mohinder, his plan was to pump Mohinder for information and kill him at the first available opportunity. When he actually met Mohinder, though, he changed his plan and decided that the two of them had a ~*destiny*~, which of course didn't have anything to do with how incredibly good-looking Mohinder is.