S.J.
I have a Baby Trends side by side jogging stroller that I love for my twins. It will take each child up to 50 pounds so it lasts quite a while. I bought mine used and have replaced the tires and tubes and otherwise that is it. I love it! The down side to it is that not all stores have doors wide enough to fit it through. But if i am shopping I normally use two carts or I wear one and put the other in the cart.
Another one I looked at was a McClaren. It is also a side by side but instead of being a jogger style it has the double wheels like normal strollers but has a better turn radius and fits down the majority of store aisles and fits through all doors.
Good luck.
S.