Gippsland Dairy (white tub, green lid) organic natural yogurt is also fine - I look for natural / greek yogurts with the smallest number of ingredients in the list. Also, the "does it taste sweet"? test is always good.
I agree with David about being suspicious of artificially sweetened things so stay away from the Forme and the yello nestle diet yogurts - in my opinion, they're not yogurt, they don't contain pro biotics etc. They can be a nice treat if that's what you're after but I prefer good natural yogurt. Good luck!