Chargers? It must just be the ESPN contingent, aka the dregs, because I've found them to be almost as painstakingly polite (and boring) as the Colts fans.
Most annoying, hands-down imo, is the extreme Skins homers, with their insane euphoria each off season followed by a day or two of self-flagellation at season's end, only to be crushed by another round of manic overevaluation of their team and chances.
Plus, like their coaches, they are terrible crybaby whiners. They just can not stop bawling.
Second place goes to Patriot fans, vindictive, petty minded and grudge driven, insecure idgits, one and all. No amount of rings will cure them of their abandonment trauma, and it's resulting psychosis.
Third is Eagles fans, altho on the net they don't seem as obnoxious as in the real world. I guess that's because so few of them can write. The ones at Philly.com are pretty much vulgar, LCD dolts.