ICQ and AIM to start with. Eventually I barely used ICQ because most people moved to AIM. I had MSN but barely used it. I still remember my ICQ number... 6073961. Pretty sure some Russian stole my account. I know I had that at least as far back as 97-98, if memory serves. I used AIM until social networking sites and mobile phones rendered it basically irrelevant. I don't even really 'chat' with anyone anymore. I especially hate text messaging or typing shit out on my phone. I'd much rather just send a message from my computer because I can type 20x faster with a keyboard, but even then I don't really see the need to chat with someone for hours like I used to back in the day.