Peazip is one of the most versatile file compression and archiving utilities out there - possibly the most versatile - and it's free. It's also quite easy to use and offers the same features found in programs such as WinZip and WinRAR such as context menu integration, passwords, command line usage, etc. See all: Software utilities reviews.
Peazip supports every compressed archive format I'm aware of: 7Zip, ARC, GZ, TAR, ACE, RAR, etc. There's also support for both ISO and UDF disc images and Linux package formats such as DEB, RPM, PET/PUP, and SLP. As a bonus, you can open Mac HFS DMG files. There are more, but the point is that there's little out there in the way of compressed file you can't browse and extract from.
While I've always appreciated the effort that goes into this piece of free software, I've also installed, then uninstalled Peazip several times over the years because of operational and performance issues. This has left me using WinRAR, which while a bit old-school looking, is rock-solid and fast. Version 5 of Peazip seems quite a bit more stable, but it still has a tendency to not close and launch 100% smoothly when you're dealing with multiple instances. Also, the progress bar is still inaccurate, claiming far less progress than as actually been made. Several times, it was only 25% across when the task completed.
Peazip also did not not like that fact that I'd redirected my Downloads folder to a non-default location, complaining that it was no longer accessible. I could of course browse to the real location, but obviously Windows Vista/7/8/8.1 compatibility isn't complete. The program depends on a lot of open source and free libraries to handle the various archive types, and some of them are faster than others. That's a minor complaint: Peazip is easily fast enough on any modern PC.
One thing I most definitely do like about Peazip is its interface, which is clean with lots of nice little touches. For instance, it ignores unpopulated higher-level folders when you open archives. E.g. if you have a batch of zipped pictures in say "\Picture\Holiday 2013\Grandma", it takes you directly to the Grandma folder rather than forcing you to tunnel down three levels. Also, it keeps the files that you've already viewed open till the archive is closed. This is handy when you're using the Windows image preview and want to scroll through the pictures you've selected to view from within the archive without permanently extracting them.
There are other compression utilities out there: WinZIP, 7Zip, and WinRAR just to name a few, but Peazip compares favorably with all of them. I wish it was a little faster, but on a modern PC or laptop, the difference isn't as significant as it once was. I'm liking it so much so far that I may not be uninstalling again. See all: PC Advisor software downloads.