Great stuff, thanks for all the input. Some great recommendations, some of the lists contain songs that I already sing - so I'll look at them first ;-), and I found Susanna Martin on Contemplator - you're right Georgiansilver, this is a great resource - highly recommended.
It's really interesting how an interpretation of a song can influence whether you like it or not. I sing quite a few songs which are also sung by one of the recommended artists above. Thankfully I found them before I heard her singing them because her depressing (in my opinion) interpretation would almost definately have put me off!!! There's some recommendations for some artists I haven't heard of and I'll definitely give them a try if I can find them here in NZ.
It's great to hear other peoples recommendations because it opens up new ideas.