You rock

First Example:






Freddie: I’m going to
organize the biggest party of all time.
Mick: Dude, you rock!  When is this party going to take place?
Freddie: We’re going to
rent an entire farm and set up a massive sound system that all the neighbors
will be able to hear.
Mick: Wow! You’re really
putting on a show.

Meaning: “You rock” is an expression used to
show strong approval.  Since Rock N’ Roll
is a popular genre of music, it is an expression going back for some time.  However, it’s still popular in use.

Second Example:

John: Hey man, do you think you can
have that work done by the end of the day?
Paul:  I completed that work last week.  I can have it on your desk in a minute.
John:  Fantastic! You rock!  I can always count
on you.
Paul:  Thanks. 
I really appreciate your comment.