Hello
No branch can be categorised as best or worst it completely depends on your passion and interest.

Hi.
Good morning.
The simple answer for this question is that in which stream you have interest that only stream is best among these three.
But according to jobs and every thing cs is best it can give you high packages. But know a days cs is going down . Mechanical can give you maximum  of 10 lakh per annum and you also have high scope in government jobs and civil is also same. I telling you again go for your interest. If you ask me I always say mechanical is best according to me.
All the best!!