I personally use AIM, ICQ, MSN, and IRC. All work pretty well and all are quite simple. Although I can handle ICQ, it bothers me frequently. If it cannot connect (2003 v) it just keeps reminding me and keeps coming over my current work/play with a message, which is a real pisser. AIM is good if you use AIM+ which is a wrapper by
Big-O-Software that logs all conversations, strips out ads, and allows windows 2000/xp transparency plus some other stuff. You need to use a version of AIM earlier than 5. I use version 4.something rather because it doensn't have AIM today and it uses a better interface than 5. In 4.something rather you can add buddies by clicking the buddies tab (or something like that). Good luck.