Okay, here's my input. At the moment I'm a 2nd year electronic engineering student in South Africa. I, personally, love studying engineering though it's one field that can guarantee that if you're a little insane, you're sure to BE insane by the end of your years of studying.
To be an engineer, I think, you should have a flair for Maths. Especially if you're thinking of doing it professionally with a degree instead of a technical diploma, the theoretical aspect of maths will ensure your great understanding of concepts you will probably only apply years after graduating.
Also, as much as I'm not really this type, you have to have a practical understanding of things. Granted (at leats I've been told) that as a qualified engineer, you can never do a practical application again - but rather just the calculations - if you can't see the solution, it ain't going to work.
Anyway, let's get onto something I definitely KNOW about - student life. Studying engineering is basically a self-imposed 4 (or more) year sentence to hard labour. You WILL have no time, you WILL have 30 odd page reports due every week, you WILL lose like a million hours of sleep, you WILL have an astronomical coffee bill, you WILL be stressed, you WILL at times have no clue what you're doing BUT if you are true engineering material, you WILL never look back and even half-consider changing your course.
I think engineering is a calling. You know, as an engineer, you are at the forefront of development and your company that you will have on campus (ie. other engineers) will be like minded people who CAN make a difference (maybe not politically but more uh...structurally) in the world. Even though you appear to have no life, engineering will ensure that you do enjoy yourself after all - as an engineer, you will "engineer" free time and yes, I know that was a dry joke.
As for the field - that's personal. You have to have an interset in that field to choose it. However, I say that Electronic/Electrical/Computer is the way if you are more mathematically inclined as mech/aero/civil etc. are very practical fields compared to elec.
Also, when I was deciding on my career path, I was informed about this "wonder" that encompasses engineering. Once in the job market, you may never ever have to do engineering again. Why? Employers employ engineers in fields which require brilliant thought and introspection. By attaining an engineering degree, it shows you have exquisite probel-solvng skills. Also, engineering does, in a way, teach you to think.
Lastly, the money is good BUT you should
NEVER
NEVER
NEVER
NEVER
ever choose a career for the money - and I'll stand by that.
Hope this helps.