A lot of people around the world use MSN, AIM, IRC, Skype, Digby, etc. They are all good instant messengers, and if you use one that isn't one of those, you can still leave a comment saying why you think the one YOU use, is better than all of them. And if you use one of those and you think that one of those is the best, then say it here.
I personally think that MSN is a great instant messenger, it has scripts, themes, groups where you can set your contacts(a lot of IMs have that though). Skype is also another one i use, which i consider awesome. Why? you can call anyone for free, it has an IM in it, and nothing is better than group calling.
