I think everyone else has great points. Go to the store and try them out. We wore our stroller out so bad there was no way it was lasting for another child. It also got torn up by airlines when we traveled, etc. The thing was a complete wreck. That said, it lasted 4 years. I just tossed it a few weeks ago in fact.
We had an evenflo travel system. It looked similar to this, with a brown plaid print:
Evenflo Aura Select Travel System - Alhambra : Target
I could collapse it and raise it with one hand, and I loved the way their infant carrier had the twisted handle so it was way more ergonomic than other carseats we tried out. It was also really nice in that when she was still little, or sleeping, the stroller cover would cover the entire stroller over here, so if I was shopping and she was napping, nothing really bothered her, and when she was a baby, I could just cover her if I didn't want to deal with people's oogly baby eyes and grabby hands!