If you go even more old school, a user in Georgia, USA (about 2500 miles away) and I played a game of Firepower over the Internet using real Amigas and a couple of serial-ethernet devices.
Worked pretty good, except for a few things.
1- For some reason, if we tried to "text chat" in game, it killed it. But the gameplay worked and we could "voice chat" on the phone.
2- (and this is the important one) I LOST every game we played!!!!
(OK, that's not in any way a surprise, but they could have let me almost win one of them!!) ;-)