Here is one more way of looking at it:
If you feel OK being able to think about entities you cannot see (electricity, transistors), consider Electrical. Somewhat related to it, you need to be very good with Maths.
If you need to see it happen more to be comfortable thinking about it, Mechanical will be a good choice (though a decent level of Mathematical ability is needed for any engineering discipline - with possible exception of environmental engineering).
Aeronautical is a specialization of Mechanical – you need to be OK with the fact that possible employment is with only a few companies and in a few cities.