I really really like our Maclaren Triumph umbrella stroller. I can throw it on my shoulder and carry it around anywhere, it maneuvers great, the basket is a good size, it's sturdy - it's great. Plus it's really light - 12 lbs, I believe. I've used it since my daughter was 7 mos and now she's 2 1/2 and it is still great.
We also got the Britax Roundabout when my daughter was 7 mos and she's just now approaching the height limit (the weight limit is 33 lbs). It's fine since she needs a new seat and we're having a new baby who will use this one in about 6 mos. However, in retrospect I would have gotten the Britax Marathon because it has higher weight and height limits. Or I would have looked into the SafeGuard Child Seat, which is highly impressive though VERY expensive. Still, that's a seat that would last until your child's ready to be out of a 5-pt harness, so I'd think worth the investment.