Why Pidgin? Well, if you were a Linux user you'd see it already preinstalled on most of the major flavors of Linux so you can rest assured that this is tried, true and tested for good user experience.
Pidgin is compatible with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, MXit, MySpaceIM, and Zephyr. It can support many more with plugins.
Give it a try on your Windows or Linux PC by visiting here.
