Deepburner - CD and DVD burning software which can do iso images too.
Alcohol 52% - Virtual drive allowing you to mount a disc image form your hard drive.
uTorrent - for downloading torrents
Trillian Basic - Great if you are fed up of MSN crashing, also works with AIM, ICQ, Yahoo Messenger, and IRC and with plugins it deals with checking gmail as well as other pop3 email accounts, rss and various other stuff. I think you can also get a Skype plugin too.
I'm a fan of
Download.com for sourcing free software, you can choose your operating system and whether you want free software, trial or any software.
Arfie