CHICCO, hands down!!
My husband and I are expecting our first baby and just went and bought a Keyfit 30. I've not even got to use it yet and I just can't seem to live without already.
The PEG is way to expensive for something that's not going to be used that long, and I absolutely hate the PEG base.
The graco Snugride is nice, and will fit in such things as a shopping cart and stuff, but the Chicco is just great.
The cons to the Chicco however are that, like I already stated, they won't fit in a shopping cart seat basket like most and have to be sat in the basket area, but I figure if you're going shopping long enough to need the baby seat then you going to be getting a lot I'm sure and don't need you baby in the cart at all, put him/her in a nice sling and carry them, or get a sitter, lol.
The other con to the Chicco is the sunvisor. It is so darn short, but the Keyfit 30 has a little more mesh material added on to it to make it work for baby.
Even with those cons though I bought it, and like I said I already love it.
We got both the strollers to go with it as well, the Trevi and the Cortina. My husband drives a truck so the Trevi slides right in the floorboard between the back and front seats. Plus, it's great for the outdoors, and when we do go anywhere outdoors like we take the truck, so the Trevi will be great. And the Cortina is rather large, but fits in the trunk of my car (2007 Toyota Camry) pretty well.