Hi DJ,
I've been using Trillian for a few months now, and I think it's great! If you have contacts in different mediums, i.e. MSN, Yahoo, ICQ, etc, you can view then all in one window, and have conversations with all the different Messenger clients, just using Trillian (you cannot cross talk with different mediums). This obviously saves having several different messenger programs on the go, if you have contacts over multiple mediums.
I also like it because I find the layout a lot neater than with MSN / Windows messengers, and you can rename your contacts, so that the person's name, rather than the complete e-mail address, appears. It's highly configurable, and although Trillian doesn't do
everything messenger does, it does everything you need in a basic messenger service. It's also free and contains no ads or spyware.
One thing I must mention is that there is a problem with file transfers if you are running Norton Firewall. You can receive but not send. I use Sygate Firewall, and it works fine with that.
Try it - you might like it!
www.trillian.cc