While WinRar and WinZip are dominant apps for Windows, WinRar's support for Mac comes in the form of a command line only interface and WinZip wants you to purchase the app after the trial is over. Windows definitely has more free options like 7-Zip which can extract a variety of different formats. Mac users have been a lot more limited with OS X natively only supporting zip format.
Winrar isn't the best solution either because it only supports a command line interface. This means you'll be stuck using lines of text commands to complete the task you want. It's confusing for someone who has never really used Terminal. A great alternative is called The Unarchiver. This free app supports OS 10.6.0 and higher and supports zip, rar, 7-Zip, Gzip, and Bzip2 formats. It dives even deeper with support for older archive formats. The main formats you'll probably deal with are zip and rar and The Unarchiver handles these with no problems.
Using The Unarchiver
The Unarchiver is a very simple app to use. If you have different archived files on your computer and need to extract them, simply click on them. This will load either a one-click function where it will decompress the file in the same parent folder as the original. Or you can set The Unarchiver to ask each time it runs. If you choose for the program to ask each time it runs, it will open Finder and you can choose where to extract the file.
After you select the archive file you want to extract, The Unarchiver will extract the files into the location you chose.
Keep in mind that The Unarchiver is only an app that extract files. It won't create archive files. You can create zip files through OS X's Compress option though. If you deal with a lot of archived files, The Unarchiver is a great free option. There are other paid apps, but if all you're looking for is a quick and painless way to extract files then this is the app to use.
[Original article published June 2010] Add me on Google+