as of now, everyone interested in compressing stuff should use WinRAR. It's freeware, and expires after like a month, but it still functions perfectly.
Good features on it for rightclicks... i most often use it for mass decompressions... I dont like opening ZIPs or RARs one-by-one and dragging the files out... with WinRAR, select all the RARs or ZIPs and select "extract..." or "extract here"... the former lets you put all the files into the same folder, which is default as a copy of the name of the current folder with only the compressed files in it, and the latter puts all files from the ZIPs or RARs in the same folder as the compressed versions.
RAR (pronounced "rare" i believe) is quite basically the second best format for compression, falling behind the currently-unused *.7z format. RAR is popular and very useful.