Just a warning.
After exhaustive research, I decided to get the Chicco Keyfit30. It's more expensive to start, but I like that you get more than 4-6 months of use out of it. It gets good feedback from parents and certified carseat techs have rec commended it as well. (I've totally been lurking carseat boards. I have way more info on this topic than I thought I 'd ever need!) Some people balk at the weight, saying that you wouldn't keep carrying it around because it'll get too heavy, but really, who cares if you eventually just leave it in the car and carry your baby another way? Just because it can be used as an infant carrier doesn't mean you're obligated to use it that way when it's uncomfortable.
I didn't place it on my registry yet because as of now the only color out is an ugly orangey-tomato color and I'm hoping the rest of the options come out before November.
I was at Target yesterday and I scored an awesome deal. I picked up a Graco SafeSeat1 (SS1) for just $32.48! Brand new, manufactured this year! They're not carrying them any longer (at least in stores) and I got the last one. They still have them available online for their full price... $129.99! So awesome. So for less than the price of a second infant base I got a whole second seat. This was my second choice seat (again, because of the higher height/weight limits) so I'm totally thrilled with my find. I still kinda want the keyfit, but for now I'm basking in the glory of my excellent deal.