I look for as complete a multi-mineral (containing more than 4 or 5 minerals), with multiple chelated forms. In capsule form if possible. I also take extra magnesium to bring my cal/mag ratio to 1:1.
I was taking Vitamin Shoppe brand for a long, long time, because of the number of minerals and multiple chelation. I had to hunt for a long time, but I found something similar in Solaray's Mult-mineral.