I agree it is nice to begin a game with a "Hi" or something similar, and likewise to respond positively to someone else's greeting. If the other side doesn't respond, I don't take offense, since perhaps he didn't see the message or just prefers to play quietly. Additionally, I think it's nice, at the end of the game, to send some nice words or even a trophy if it's appropriate. I take offense only when the opponent sends an uncalled for remark.
Chat rudeness

Hi................................. Great stuff, that "hi". I wish there was a hi trophy I could give my opponents at the onset of games. Then they would acknowledge me, for I crave acknowledgment!
Try to figure out a way to say it with chat disabled.
I just have to say some players are generally good at maintaining friendship in regards to chatting,you don't have to spill out your life story but when someone says "Hi" i believe you should reciprecate something,and if they don't, it gives me more determination to beat them than ever.A chat forum is as much apart of this site as is the chess,just a simple response is adequit.What say you?