I like Yahoo messenger. But I'm one of those freaks that likes yahoo in general, so you may want to take everything I saw with a HUUUGE grain of salt.
Nah, just kidding. Really, if you're not on Yahoo messenger, you should try it. Because MSN is the spamwich king of the universe, and AOL is the devil. Really. It is.
Yahoo messenger lets you log in invisibly. I canNOT stress how important this is. People may have you on their friend list that you just don't want to talk to, but feel it would be cruel to block. Like your dad. You can't block dad. But you can go online invisibly, and he won't know you're there! MSN won't let you do this until you're ALREADY ONLINE, which defeats the whole purpose of the invisible button! I don't want to change to "invisible" after everyone's already seen me! And AIM (the devil) doesn't have an invisible button. I bet it's there, but I just can't find it. Which means that it wasn't very well organized. What a shock. I wouldn't know, I haven't even downloaded the last 3 versions of it, I hate it so much.
You can access chat rooms from your yahoo messenger. You can't do that from MSN. And AIM is the devil (as I've said before). And Yahoo Chat is pretty cool, the separate "private message" windows are just regular IM windows, so you can have all the options you would if you'd just message a friend--adding them to your list, putting them on "ignore", seeing their webcam (yahoo lets you see webcams now, BTW), changing the font/colors of your text, etc.
You can check your yahoo calendar, stocks and more from yahoo messenger. It also lets you know when you get new Yahoo mail.
Overall, I use this messenger much more than MSN (you can't avoid MSN, it's just everywhere. That doesn't mean I have to LIKE it). And one fingered rats from Pluto use AIM more than I do, I just hate it.
So I'd suggest yahoo. Nearly everyone's on it, anyway, so the odds that you and your friends can get together and chat are fairly high.

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