Crossloop – http://www.crossloop.com
Show My PC – http://www.showmypc.com
Teamviewer – http://www.teamviewer.com (Highly Recommended)
Logmein – http://www.logmein.com/
Goto My PC – http://www.gotomypc.com
Remote PC – http://www.remotepc.com/
Goto Assist (by Citrix) – http://www.gotoassist.com
Netviewer (by Citrix) – http://www.netviewer.com
YuuGuu – http://www.yuuguu.com
Tech In Line http://www.techinline.com/