I like Sweet Leaf liquid stevia the best. I use the flavored. Vanilla Creme is my fave, and the English Toffee is good too, especially with a baked apple. The Chocolate Raspberry is just so-so, not much flavor.
The powdered I've tried was awful bitter. I also like Truvia, which is a blend of stevia and erythritol. But I could only use two packets a day or else my weight loss stalled.