Decaflon

I use Gaim. I hadn't had an account since college, but we use it all of the time at work. Unfortunately, it has become a crutch that prevents me from learning how to accurately transfer calls.

I use Adium too!
Love it! =)

Before that, when I used to have Windows, I'd use meebo.com =)

i don't even know if i already replied, but im using adium

I use Trillian when in Windows, GAIM when in Linux and Adium when on OSX. Adium is by far my favorite messenger. It's interface is just so gorgeous... meanwhile default Trillian looks like it might have emerged with Windows 3.11.

adium, all I need.

Hmmm.... AiM is what I use the most... but Yahoo is something I occasionally use as well.

Skype and Aduim, primarily for talking to my girlfriend when we're not together.

I do talk occasionally with people from my old workplace through iChat though.

I use MSN most of the time, with some AIM throwen on the side. Both of which with Adium of course.

And to answer a three month old question, seanrox, you can use MSN without a hotmail account without much effort. Just go to passport.net and add your current email to their system. Once you've done that you'll be able to use MSN with that email instead.

Windows Live Messenger, simply because every single one of my contacts use it... bar 2 people on AIM

Google Talk and Meebo, when necessary.

I like GTalk a lot, but the messenger I use is Kopete, through which I can access different accounts.

I don't like to install instant messaging software
so I always use Meebo.com

and recently a Meebo Firefox add-on was released

Piding is a blessing, specially when I moved over fully to Linux....No more windows.....

As for platforms, I prefer GTalk over all the others, but still use MSN (using passport) and Yahoo!

Can't wait for the time to come when all IM platforms can work cohesively with just one id!

I like Pidgin, too, because it works together with many other IMs.
...I think it won't be long until the Jabber protocol asserts itself.

I actually just started using a new IM app called Digsby. So far it's pretty nice and offers a few features that I haven't seen before--like Facebook and Twitter integration. It's still in beta, so it still is under pretty active development and will probably improve.

Now i prefer Pidgin, because of its wide choice of protocols, which can be run at the same time. So I am able to communicate with friends using ICQ and GTalk protocols at the same time. Moreover although it is based on GTK, it is able run current windows theme, so its usage is not disturbing although I am keen on minimalistic desktops.

I use Skype for VOIP and some instant messaging, I use Pidgin on windows and linux for most of the major protocols (AIM, GTALK/Jabber, MSN) and use Adium on Mac for the same thing.

I used to use MSN messenger for IM as for a while there it seemed all my contacts had one....But then I managed to spam all my contacts (including my grandparents...cringe!) after forgetting to log out in an internet cafe while traveling. Not cool.

Now I mainly use Skype. I've tried Yahoo, Google Talk and ICQ just because I had a couple of friends using it, but I prefer Skype.

The new Trillian isn't bad (it's still in beta). I never thought of using Skype for instant messaging. Hmmm...