We got the Baby Trend Sit and Stand Plus and absolutely LOVE it. It is a convertable stroller, in that it initially has two double seats, and then when your older child is ready, you can take out the back seat. It then has a place where they can stand, or they can sit on the little bench in the back. Our two-year old loves riding in this thing. He thinks it is so much fun to stand and look at his little brother. He thinks it's a fun ride. Then, when he gets tired standing, he doesn't mind sitting on the bench seat at all. With our first child, we had an Eddie Bauer Travel system. We were able to use the car seat from that stroller on the Baby Trend Sit and Stand for our baby. The way it is made, it looks like almost any car seat would fit on there.
This stroller is not as bulky as a lot of the double strollers, which is a definite plus. It doesn't quite have the same "off-road" tires that our Eddie Bauer stroller has, so you have to push a little harder if you're going over grass, but it really isn't that big of a deal.
We got our Baby Trend Sit and Stand online at Stroller Depot. Below is a link for the stroller that we have. Can't say enough good things about Stroller Depot, or this Stroller. Highly recommend it.
http://www.strollerdepot.com/moreinfo.php?SKU=1002