I would generally recommend to get an NCCA accredited certification such as ACE, NASM or ACSM. Those are nationally recognized, and you cannot go wrong with either one of them.
One consideration would be what you plan to do as a personal trainer. If you have a place in mind where you would like to work, I would inquire whether they have a preference.
All personal training certifications touch on nutrition, and by now there are plenty of specialty certifications around on nutrition. However, unless you become a registered dietitian (which is a lengthy process) you will be limited as to what you can do with any of those specialty certifications. For example, it will not be in your scope of practice to provide meal plans to your clients unless you are an RD.