ICQ, when launched, took attention of the whole world, especially Indians. Its easiness and combined with all the features make it my favorite choice of chat software, well atleast for now! ICQ has all features inlcuding birthday reminder which to me is very helpful because next time I can be reminded with a hyperlink to send a birthday card to one of my friends. Also, ICQ has good chat features inlcuding 1-on-1 chat and group chat, although I have never used the group chat. There are also plugins for ICQ for doing all sorts of things. One of my favrotie ones is BuddyPhone which is a pc-pc phone service which has integrated its software with ICQ.
The only thing I am afraid about is that since AOL has bought ICQ, they can do anything to it. I really don’t want to see any changes that are not asked by the ICQ community but I am afraid AOL will take some big decisions to yeild some quick bucks from it... and that shall lead to the collision of ICQ, if ever! THere are rumors like AOL might put banner ads in ICQ just like they have in AIM.