The truth is that it is not possible to tell one better from the other. Both of them have their own merits. They are different lines of engineering that sometimes come in unison. Job opportunities are galore in both the fields.

More often than not, it is the matter of personal preferences. If you get overwhelmed by the structures and construction, civil engineering is the one for you. If you are intrigued by the machine designs, their mechanics and dynamics, go for mechanical engineering.