gTalk by default, but Skype is my choice.

I use Adium to connect to AIM /and/ MSN. I pick AIM over MSN when possible though.

Adium for:

gTalk
MSN

and Skype for audio

Adium

I use Adium to connect to gTalk, AIM, and Yahoo!. Most people I talk with online are through AIM.

iChat is my favourite at the moment. i've had a few of my friends switch recently and now i can do video chats, Adium hardly gets a look in for me. So, #1 iChat, #2 Adium, #3 Skype, #4 IRC ( Colloguy ), #5 Two plastic cups with string between them, Im waiting for the next upgrade so i can do file transfers too.

__
GOO

I use Adium because my classmates are on MSN, and I have a lot of friends on AIM, ICQ, and Yahoo as well, and I don't want to run multiple programs. I only use iChat for videoconferencing (rarely).

I have a trip with skype but msn will do too.

We´ll always have Paris! Humphrey Bogart

MSN, AIM, and ICQ all in one

-------------------------------
Infinite Style

with some mods and plugins it's like adium for windows :D

most of my friend use msn, but i hate the program itself!

//Static

I use Adium to chat on MSN, Gtalk and AIM. I have accounts for pretty much every messaging software, so I love the flexibility of not having to run multiple programs and chew up valuable resources in the process.

http://www.slideaway.ca - portfolio

http://www.modsuperstar.ca - now with 23% more iron

I checked out on Adium and it´s not that bad at all, it´s as having one switchboard for all the incomming chats and having the chance to answer them without going crazy... Good for Adium it´s a Good addition for us Mac users...
Later.
Caya

We´ll always have Paris! Humphrey Bogart

with Gtalk, msn, icq, ichat and skype as standalone

BlankPage

I use AIM, gTalk, iChat, AIM and MSN accounts on Adium and Skype (standalone also).

Spencer E Holtaway
Graphic Designer

I use Gaim at home on my Linux box, Adium at work on the Macs, and Skype on both for audio chatting.

Communication Tube - ICQ,MSN,GTalk web-client - CommunicationTube - It’s a free web-client for the popular IM (internet messaging) networks which currently supports ICQ, MSN Messenger and Google Talk. The biggest advantage of CommunicationTube© that it’s completely web based, no software download required. It makes CommunicationTube© very convenient for people using public internet access such as internet cafe. With CommunicationTube you can be connected to multiply IM system simultaneously from one single web-based interface.

I mainly use Adium for .Mac (AIM) and MSN. I sometimes use iChat with my .Mac account, but it depends which of my buddies are online. I don't really have a preference between the two. I spent a long time customising Adium to make it super minimalist and clean.

One nice tip I have found is that if you have a .Mac address and use that as your main client you can also register your mac.com email address as an MSN Passport (as you can with any email address) and then you can use that for chatting to MSN users. This means that you only have to have one chat ID to use and remember. It makes it a lot easier, especially on email sigs and business cards etc.

I also have Skype, but know about 2 people who also use it, so it is a bit of a non-starter really.