I agree, Cosco Scenera, which is a very basic but light weight seat. Rear-faces to 35#, Fwd faces to 40lbs. Height-wise, fits children until they have about a 15" torso (some kids outgrow these seats by age 3 to 3-1/2yrs old fyi). This seat usually requires a chunk of pool noodle or tightly rolled towel when installing it rear-facing. For $45-50 though, it's not a bad deal. You just will probably need to replace it with a bigger 5pt harness seat down the road.
Another option that is a little bit plusher, and also EPP foam lined, is the Safety 1st Avenue. This seat has the same limits as the Scenera except the top slots are an inch or so higher, so kids will last a little longer in it height wise. This seat also may be a little easier to install.
If you want something that will last longer, you might also consider the Evenflo Triumph ADvance (rf to 35#, ff to 50#), the First Years True Fit (rf to 35#, ff to 65#), the Sunshine Kids Radian65 or 80 (# denotes ffing limit, both r/f to 35# and have 18" top harness slots. Tall seat that may be difficult to install r/fing in small spaces like airplanes & smaller vehicles, though). There is also the bigger Britax convertibles - Marathon, Decathlon, Boulevard. All of these seats will last your LO until about age 5 or possibly longer since the top slots are also at least 17" tall. Of course since all of these seats fit bigger kids, they are also going to be a little bulkier and heavier for carrying through airports. The Radian does fold for travel though.
hth!