I've used MSN Messenger Live, Windows Messenger, AIM, Trillian, ICQ, XFire, Yahoo
MSN Messenger Live/Windows Messenger - You will get the least spyware and the most functionality out of these 2...I recommend going with the Live version.
AIM - This is what everyone in college used. This also pops up a webpage when you log in. This can be turned off in the options. This does have advertisements running at the top part of the window...but rarely gets in the way...I don't even notice it anymore.
Trillian - This is a client that allows you to bring all of your IM accounts (MSN, ICQ, AIM, etc..) into one account. Pretty cool but you seem to lose some functionallity of the other programs
ICQ - Old news...haven't used in years...don't think it is as popular anymore
XFire - I use this as a chat for online gaming. The application will automatically download new patches for your games and let you know when they are ready. It allows you to chat with buddies in-game and has a couple of other cool features for gamers.
Yahoo - Worst product ever! I urge everyone to not even touch this product....they install so much crap on your computer when you install this product it's pathetic.
I use Windows Live Messenger with MessPatch (mess.be) and Messenger Plus! Live (msgplus.net).
Scott, what does Yahoo install? I have this on some other computers and I might get rid of it if it contains too much bloat. All I know about is that it tries to reset the homepage and install the Yahoo toolbar, which I declined to do in the setup.
Those are 2 of the things...they also install like a yahoo desktop, yahoo mail and I can't remember what else...I know that my mom's computer is always messed up...and she uses Yahoo religously...hell now that I think about it my dad's computer is messed up and so is my ex-step-mom's....all avid Yahoo users....hate the program and their website...I haven't been to it in years.
Those programs sound familiar, so I probably ran into them during the setup process. It does get annoying when they hide all those options behind the "Custom Setup" option, as the people most likely to not understand how to "fix" their computer when it becomes bloated will also never touch the custom installation options.
I checked one of our computers with Yahoo! Messenger installed, and did not find any of the extra programs installed. So there is a way to decline their installation, but it is likely turned on by default. I do dislike the program though, as our HDTV/computer setup has it installed, and I have not found a way to get it to start minimized. It also keeps popping up a message about a USB Camera or something like that, which gets annoying when watching a movie.
Yahoo! Messenger is definitely on my ****-list along with RealPlayer.