Honestly this is really a "To each there own" Kind of situation some people will tell you Synthetic, some standard, it just depends on your preferences. Your best bet is to stick with the recommended oil by the manufacturer.
Now if you want to go synthetic, stick with in the weight recommended for your vehicle ie: 5W-30, 10W-30, etc... A high mileage formula probably isn't necessary for your mileage and I would only worry about that if you are seeing some minor leaking. The high mileage Oil helps to condition seals and break down some of the built up gunk in the engine.
Hope this Helps!
-LeeZ