The first incarnation of MSN was available right there on your Windows 95 CD. This is assuming that you were cool enough to have the CD version of Microsoft Windows, otherwise it was hidden somewhere on those 35 installation floppies. I actually used this version for my first ever internet access. It was a very strange interface, and I never did exactly figure out what it had to offer over the standard Windows dial up networking and Internet Explorer.
For a long time MSN had been offering several large rebates for signing up for lengthy contracts for their service. You could even get a $400 rebate if you submit to three years of their service. I believe Compuserve was the first ISP to use this tactic, but MSN quickly jumped on the bandwagon. Here is how it worked, you simply went into any retailer that they were partnered with, Best Buy worked if you were in the United States, and then picked out a whole bunch of merchandise. You then went up to the cashier, and fill out some paperwork that signs you up for an account, and then you would get $400 subtracted from your bill. Many stores used false advertising on their high ticket items by including this "discount" in the advertised purchase price of nearly everything they sell. Check an old Best Buy advertisement for a good example.
MSN is decent as an ISP as long as you don't install their software. I used to use MSN, (my roommate got the $400 rebate). I have successfully accessed the internet with my MSN account from Linux, Free BSD and BeOS.
I cannot stress not using the MSN cd enough. The software on the MSN cd will totally hork your computer over. Well, its fine as long as you are not on, (or never try to be on), any kind of network. You will find your computer attempting to "dial up" to access your local network, and it won't stop trying to autolaunch the MSN dialer no matter what you do.
Today the MSN software has a distinct look that reminds me of what AOL for Macintosh would look like. It comes bundled with Windows Messenger and MSN Explorer. This version provides a very "AOL-like" experience, moreso than any of their previous versions.