What test is better

Kristin
Hey guys, 
What is everyone's favorite Test to use. I have been trying for a year and never even came close to a faint line and yesterday I used a first response curved test and got a vvvvvvvfl. Today used the same kind of test and nothing. It's horribly disappointing and I need to know what is best to use from now on. I am only 8dpo. Thank you.