According to Wikipedia, "An uninstaller or deinstaller is a computer program which is designed to remove all or parts of a specific other program or application. It is the opposite of an installer. Some software vendors ship an uninstaller with their applications. A third-party uninstaller is a program which uninstalls programs from vendors different from the uninstaller vendor. Such uninstallers often aim to support uninstallation of a number of programs."
The most popular option in the third-ever Poll on Uninstallers was Windows Add or Remove Programs with 78 votes out of 323 total, which is 24.1%.
It is interesting to note that this is down significantly from last year's overwhelming 54.7% for the Windows utility. It seems that quite a few people are now at least testing something else. There are some people out there who approach uninstalling programs from another direction, using methods such as imaging or sandbox programs.
Second place in the poll was Ccleaner with 53 votes, which is 16.4%.
Third place in the poll was the "Program's supplied uninstaller", with 40 votes which is 12.3%.
In fourth place was Revo Uninstaller with 39 votes, which is 12%.