I did originally vote "I'm not from your country" but then I realised that ABC might be the "Australian Broadcasting Corporation" in which case it would get my vote.
I've gotta go with CBS. I watched CBS's last couple football playoff games leading up to the Super Bowl... they were in high def. I watched the SB on ABC in HD. The HD shots on CBS just looked "sharper". However, ABC had way more standard definition shots on replays, alternate angles, etc... and those SD shots looked WAY worse than CBS's standard shots.