League of Legends (LoL) Question: Best adc at the moment?

Jinx!

I feel that Varus, Twitch, and Vayne are all good adc's, although most of them focus on your skills.

Ezreal and Varus are probably two of the best ADCs at the moment, even accordingly to op.gg in Korea. There are other ADCs that can do well like Ashe, Draven, and Twitch. Honestly, those ADCs would be great, and other ADCs work well too. It also depends on your mastery with the champion, and I do not mean just mastery rank.

Varus is very strong atm, especially Guinsoo build. You just need to kite and shoot, that's all.
Twitch is good option for soloQ, good position + R = penta LUL.

I personally think ashe is a great pick, her stun is very versitle and her E is nice to have to look down lane, vayne is also a good choice she does a good amount of damage and is fun to play.