Before Netscape and Internet Explorer, there was the Mosaic Web browser, which was originally a freeware project designed to enhance the World Wide Web and develop an easy-to-use point-and-click browser. It succeeded wildly, leading to the rise of Netscape (now owned by American Online) and Microsoft's rival Internet Explorer. Microsoft's successful attempt to destroy Netscape resulted in the code for Netscape being released into the public and made free of charge…and this was the inspiration for the Mozilla Project. This is an ongoing project to improve and modify the original Netscape code to make it more efficient and easier to run…while steering clear of the mega-corporate shopping garbage being dumped into each successive version of Netscape. The browser still looks very similar to Netscape, so it is very easy for Netscape users to adapt to Mozilla. And best of all, it is entirely free.
If Mozilla itself is not to your liking, then there's Firefox, which is a more compact offshoot of the Mozilla Project. This is fast becoming the browser of choice for many people sick of the numerous security flaws that have plagued Microsoft's Internet Explorer.
Firefox has a built-in pop-up blocker to prevent those annoying, spamming ads from wasting your time (and possibly infecting you with spyware). However, as the browser has become more and more popular, enterprising and tricky spammers have found ways to get around it and pop up their spam on your screen; this means it's still necessary to use an external pop-up blocker such as Panicware.
One clever bunch of hackers has even come up with a utility to turn your Internet Explorer browser into a clone of Firefox! It's called Foxie, and you can get it at: http://www.getfoxie.com
(A word or two should be said in favor of the original NCSA Mosaic. The development of Mosaic ended in 1997, with the foundation of Netscape (which made a profit, rather than being nonprofit). But the final release of Mosaic is still a damn good Web browser, able to stand tall with Netscape… and it's still free. It was released before the introduction of Java, which is considered a big plus to many folks because it doesn't leave you open to all the traps that advertisers, spammers, marketers, and troublemakers have used to trap you when you visit Web sites for the first time.)
Extentions: (The Mozilla-y name for plugins)
http://adblock.mozdev.org/ To block banner ads (eitherspecific images, directories, video/audio files or flash movies)
http://roachfiend.com/archives/2005/02/07/bugmenot/ To bypass those pesky logins to places like the NY Times Online