There are many software vendors that bundle third-party applications with their software.  This is a controversial practice at best, or down right despicable; depending on your point a view.

Calendar of Updates has been compiling quite a list of applications that come bundle with third-party applications.

Calendar of Updates - Installers Hall of Shame (unwanted add-ons) - Calendar Entry (for the current list)
Calendar of Updates - Post your dodgy installers which pre-check things, A collage for our members to view? - Forum discussion

CoU’s - Installers Hall of Shame - as of 06 July, 2008

• Adobe Flash Player - Google Toolbar
• Adobe Reader - eBay Desktop
• AOL Instant Messenger - AOL Toolbar
• Apple’s Software Updater - Safari Browser, QuickTime, iTunes
• Applian FLV Player - Yahoo Toolbar
• AVG 8 - AVG Security Toolbar (Yahoo Search bar)
• BitComet - Google Toolbar
• CCleaner (standard installer) - Yahoo Toolbar <<<Offers ‘Lite’ version, without toolbar
• Comodo Firewall Pro - Ask Toolbar (This toolbar is detected as spyware/adware by several vendors)
• Cyberlink PowerDVD 8 - Google Toolbar and BETA of Moovielive
• Daemon Tools - Search tool and sponsor ad module
• DivX - Yahoo Toolbar
• GoogleTalk - no addon but will change default search setting of IE
• GoogleEarth - Pre checked Google Toolbar installation
• ICQ 6 - ICQ Toolbar
• Iobit advanced one care - Yahoo Toolbar (selecting no will still do changes on the system)
• IrfanView (Google Toolbar for IE and Google Desktop Search)
• Logitech Setpoint (Logitech Yahoo! Toolbar)
• MP3 WMA Converter - Yahoo Search and Delio Comparsion Shopping Toolbar
• Nero Burning Rom - Ask Toolbar (This toolbar is detected as spyware/adware by several vendors)
• PC Tools Firewall Plus - Google Toolbar and Threatfire
• RealPlayer - Google Toolbar
• Shockwave Player - Norton Security Scan or Google Toolbar
• Skype - Google Toolbar
• Spyware Doctor - Google Toolbar
• Spyware Terminator - Web security guard, Crawler
• Sun Java RE (online installer) - Google Toolbar
• Sun Java - OpenOffice.org
• Trillian - Ask Toolbar and Weather Channel Desktop
• Veoh media player - Yahoo toolbar, search engine change & search protection
• Webroot SpySweeper - Ask Toolbar (This toolbar is detected as spyware/adware by several vendors)
• Winamp - Winamp Toolbar
• Windows Live Installer - Windows Live Toolbar and Sign-in Assistant
• Windows Update - Windows Genuine Advantage Notification - (pre-checked, not required, should not be high-priority)
• Windows SteadyState - Windows Live Toolbar
• Winzip - RegistryBooster
• xplorer2Lite - Conduit toolbar
• YaHoo! Instant Messenger - YaHoo! toolbar, with ‘YaHoo! Search Protection’ and homepage change to YaHoo!
• ZoneAlarm - SpyBlocker (Ask Toolbar) (This toolbar is detected as spyware/adware by several vendors)