When it comes to dairy free, it gets a lot hard for me. I have found few items to actually taste as good as the real thing BUT here are some that I think are very yummy and just as good.
For Cheese, cheese spreads I use Daiya, Their cheese actually melts and tastes really good. GFDF!!
For Butter I use Earths Best. They have a variety of soy free, dairy free, and much more. It’s so good.
For Yogurt I have a few I love. For soy yogurt I use Silk fruity and creamy, they also have an almond yogurt too BUT my favorite almond yogurt is Amande. There are also yogurts made from coconut milk. So Delicious.
A lot of these companies make good “milk” and other products as well,
For Sour Cream, hands down is Tofuti’s. http://www.tofutti.com/dairy-free-cheeses/sour-cream/
I hope this helps a little for the GFDF folks like my family.
Happy Gluten Free Eating!!