Skype Alternative For IMers

Can we all agree on this: Skype Officially Sucks?

1) They don't allow new account to register with username, live:xxx bullshit etc
2) Using skype on both phone and PC is just horrible. Lots of bugs.
3) Doesn't even remember chat history correctly.
4)Skype credit BS.

So what are the alternatives? So we can ask for that alternative without asking for skype ID.

Obviously, we can't share our personal mobile numbers
So, apps like whatsapp are out of the question.