At the current point in time, I'd say mechanical. Most employers don't even know what mechatronics is, and are hesitant to employ someone with such a degree. (See even the spell check here doesn't recognize it as a word)
HOWEVER, this might completely change in the next few years because with a lot of mechanical/electrical and software systems coming together in the growing field of robotics, people will probably look for multi-skilled engineers, and therefore mechatronics ones.
The best thing (although itl'l take a few more years) is to do a mechatronics degree, and THEN do either an electrical/software or mechanics degree after that. Because mechatronics 1,2,3 years cover similar subjects to all of these degrees you should get a lot of exemptions that reduce the length of the second degree to only 2-3 years.