Britax Marathon, Decathlon, or Boulevard: 17” top slots, rear facing 5-33lbs (newer models rf to 35 lbs.), forward facing up to 65lbs in 5 point harness. Great seats, allow for rear facing tethering, have lockoffs to replace locking clips, very easy to install, last most kids to age 5-6y/o. $220+
Evenflo Triumph Advance: rear facing to 35lbs, forward facing to 50 lbs. Max harness height of 17”. The Triumph Advance has the infinite-like harness adjuster to which means no re-threading the harness. Probably small enough for newborns. Harness not removable. $129
Sunshine Kids Radian 65/80: 18” top slots, RF 5-33lbs, FF up to 65lbs in 5 point harness. Great seat, only second to Britax because it has some compatibility issues in some vehicles when installed with seat belt. Harness not removable. Really good seat otherwise, allows for RF tethering, lasts most kids to 6-7y/o. 8yr lifespan (most have a 6yr) $175+
Recaro Como & Signo: RF to 35lbs, FF to 70lbs. Bottom slots of 9", so not ideal for newborns. The outside width of the seat at its widest point is approx. 19 ½” to 20”. The Como & the Signo are basically the same shell the biggest difference is that the Signo has an infinitely adjustable harness (whereas the Como has to be re-threaded) and the Signo's latch straps are on a bar--similar to Britax (on the Marathon and Boulevard)--so you don't have to re-thread the latch belt if you're going from rear facing to forward facing. Como is $249; Signo is $289 and has 17.75” top slot.
First Years True Fit Convertible Car Seat : RF 5-35 lbs, FF to 65lbs, 10” bottom slots, 17” top slots. 3 crotch positions, designed to fit smaller cars—headrest removes to allow rf seat to recline to 45°, put headrest back on after older child is 22 lbs. and adjust seat to be more upright when rf. Cover removable without unhooking the harness, lockoffs for rf & ff, harness adjusted with a knob, everything adjusts by sliding something. Covered in EPP Foam. $179.
Cosco Scenera: 5pt harness version. Very basic no-frills seat. 35lbs RF limit with a taller shell. 40lbs FF limit however most kids outgrow it in torso height at about 3-3.5yo due to the low 15” top slots. It just doesn’t offer enough torso grow room to get most kids to 40lbs. Usually requires 1-3 chunks of pool noodle to get a good recline. $40
Safety 1st Uptown: 35 lbs RF, 40 lbs FF, tall 16.5” top slots. EPP foam, velvety plush cover, super cushy. Very easy to use & install. 8 yr lifespan (Most have a 6 yr.). Around $100 or less at albeebaby.com and walmart.com.
The Graco ComfortSport, Evenflo seats, and the Alpha Omega 3-in-1 types are very small seats that are usually outgrown the same time as the $40 Scenera. You don’t get much for your money. While they are safe there are just other options that offer more for less cost.