Hey, if you want duets, there are some really great ones. They are (and of course there are tons more): My Immortal-Evanescence, The Prayer-Andrea Bocceli and Celiene Deion, Written in the Stars-Elton John and LeAnn Rimes, and Broken-Shaun Morgan (of Seether) and Amy Lee (of Evanescence). Of course there are many, many, many other duets that you could try, but these are four of my favorites!! Hope this helps!
~Ashton