7-Zip

• highest compression ratio in 7z format using LZMA compression;
• ZIP and GZIP formats compression ratio is 2-10 % better than ratio provided by PKZip and WinZip;
• self-extracting files for 7z format;
• integration with windows menus;
• file manager;
• command-line version;
• plugin for FAR Manager;
• localized to 47 languages;

Screenshot

Official site