Living right between Baltimore and DC, my second team was always the Senators. And DC managed to lose 2 Senators teams. Okay, I'm not quite old enough to actually remember when the first team left for Minneapolis, so I don't hate the Twins (unless they beat us this weekend), but I will always hate the Rangers.
And then there were the Colts. I'll never root for Indianapolis. Or Denver, for that matter. Blame Elway for that.
I love a lifelong, deep Sports Grudge!