There is no one best, it's just the one that fits your car, fits your child, fits your budget, and will be used properly 100% of the time. Then added bonus for buying beautiful covers.
Are you having a little girl?
This is a seat that is highly recommended. It's easy to install, easy to use, and fits babies from preemie size on up to usually at least around nine months. A small child might get 18-24 months out of the seat. A large one about six months.
If you find that you use it, love it, and have a second baby later you can always buy a more gender neutral cover if the situation requires it. Something to keep in mind for later with such a gorgeous but girly cover.
One note I tell my clients who have any Snugride seat is that when you're done with it reset it right away to the newborn position. As you're adjusting it over the months you'll see it has extra loops at both the ends of the shoulder straps and hips straps (they're each one strap, but the shoulder end and hip end). It's remarkably common for parents who have a Snugride to forget between babies that they need to put the loops back for smaller babies after their first baby grows. So then they come here saying, "I don't get it, it fit my first baby who was much smaller!" So I tell parents to reset it to the newborn position when you're done with it, rather than when you need it again, so it's more fresh in your mind.
Wendy