Go ME man. The only true engineering categories (I know I will get flamed for this) are Electrical and Mechanical. Think about it: in any engineerign discipline, you end up modeling stuff using circuits or basic mechanical systems (springs, dashpots, tubes, etc.)
No disrespect to anyone, but I will never understand how people willingly go into civil or industrial engineering -- but I digress.
I recommend that you stick with mechanical engineering because if you later decide you still want to do civil, you have a better chance of getting hired based only on your BSME, and you will not have to do much adjusting. Try getting a job designing internal combustion engines with a BS in Civil Eng. as your best chip -- I don't see it happening so easily.
I was doubling as ME & EE my first year in college. Then I became fascinated with digital media, so I decide to double in EE and DM.
I am working as an EE at the moment, in the controls industry. I can tell you that you will have much more fun options as an ME than a Civil engineer.
You should be able to get a job as an ME pretty easily. As a Civil Eng., you will neeed there to be some sort of economic/infrastructtural growth, whereas mechanical engineers will always be necessary.
Also, I would give myself another year to set the decision in stone. Take the intro courses for both, and talk to upperclasssmen and ask lots of questions and inquire about their senior projects, etc. Also, you will have a better idea of how you feel about things by the end of your second year.