What is the best sensitivity to play csgo?

The sensitivity is all up to your preference, I normally play on a 400 dpi and around 0.45 - 0.69 sens ingame. But again, it's all up to your preference

Dude! I dont know! Really! But, I want to write a message XDDDD So, I actually play as default XD

I play 400dpi and 1.6 sens and I'm very good player

Low sensitivity and low dpi is the best
I use 400DPI and 1.5 ingame sens

I play super slow sensitivty so I can land shots on the head. I play around .7 and a very low DPI

I play with low sensitivity (1.50) with 400 dpi better accuracy

It's mostly a matter of personal preference.
There's many videos on youtube that'll help you configure them efficiently.

Also, does your mouse have only 1 or multiple DPI settings?

You should have 1.5 in sens.

You get good aim. ; )

im playing fps games for long time, and almost every 2 months i lower my sens even more :D
currently on 0.4 sens and 1600 dpi

low sensivity of course, im using 400 dpi and 2.3 in game