On your Superliner long-distance trains (any overnight train traveling west of Chicago, plus the City of New Orleans and the Capitol Limited), you have the Sightseer Lounge car, with large wraparound windows that curve at the ceiling, allowing for an improved view. Seating wise, these cars have some booths in one half of the car, and some smaller chairs that face the windows on the other side.
Eastern long-distance trains (except for the Capitol Limited) don't quite have as nice of lounge facilities. Those trains are single-level tend to have cars with all booths, and smaller windows that aren't as impressive for viewing the scenery. Short-distance trains outside of the West Coast may have cafe/lounge cars that are similar to the single-level long-distance cars (from a passenger's perspective, there are some technical differences between those and the long-distance cafe/lounge cars, but most passengers probably couldn't tell the difference), with booths, or they may have half lounge, and half passenger seating (generally reserved for business class). The exact type will depend on the train.
The Auto Train, running from Virginia to Florida, has its own special lounges.
Some Superliner trains also have what's known as the diner-lounge (sometimes referred to as the "Cross Country Cafe"). This has a hybrid seating arrangement with some normal booths, and some three-seat booths that face the inside of the car. Those cars will eventually be reconfigured to have all normal booths. The upper level of this car also has a walk-up counter which can be used for food service (as opposed to the Sightseer Lounge, which has the food service counter on the lower level).
The Coast Starlight has what is known as the "Pacific Parlour Car" which is a first-class lounge. It is similar to a Sightseer Lounge with the wraparound windows, but has the "sofa" type seating you may have seen, as well as some booths and tables. That train will also have a Sightseer Lounge for all passengers (the Parlour is only for sleeping car passengers).
West coast short-distance trains have their own special food-service cars. The Pacific Surfliner actually doesn't have a lounge car of any sort, but instead has food service out of the lower level of one of the coaches. Capitol Corridor and San Joaquin trains have an upper-level lounge that also sells food and beverages. The Cascades route has two cars that serve the purpose of the cafe and lounge. The "Bistro" car is the food-service car, with a couple of small tables, but not really for lounging. The "dining" car has booths and tables for lounge seating, as well as eating. In the past, actual dining car meals were served on trains 510 and 517 to Vancouver, but I don't know if that is still the case.