The KeyFit is the infant seat pediatric nurses install in their sleep, bundled with a stroller that self-stands when folded. This is the safe, sane default for most families.
If you want one pick and no research spiral, this is it. The KeyFit 35 has a decades-long reputation for being the easiest infant car seat to install correctly the first time, and correct install is the whole ballgame for crash safety per NHTSA. The Bravo stroller isn't fancy, but it one-hand folds, stands on its own, and holds up. Downsides: it's bulky and heavy for a single stroller, and it caps out around toddlerhood with no expandability. Skip it if you're tight on trunk or closet space, or if you know you want a stroller that grows to two kids.