Many play yards, such as the Graco Silhouette discussed in Types, offer a bassinet that covers the entire length and width of the play yard. That is a good feature because it reduces the likelihood that your baby will fall into the play yard. But a baby could still fall outside of the play yard so stop using any bassinet attachment once your baby can push up on his hands and knees. The Safety 1st Travel Ease Elite Play Yard (about $112) also comes with this type of bassinet, and a changing table and removable toy bar. It measures 30 x 46 1/4 inches and has lockable wheels.
Nice to keep baby out of trouble at home. Once he became mobile we had to do an "upgrade" as we noticed he was starting to hit his head on the X shaped metal bars. We tried some alternatives but the best so far was wrapping the metal bars with pool noodles (see picture). You'll need 8 pool noodles and some cuts (buy some extra in case you mess up). Use 2/3 of a pool noodle to wrap the internal bars and the remaining 1/3 to wrap half of the external bar. The pieces will also need a longitudinal cut along the length to fit the bar in. You'll also need some small cuts in the middle of the longer piece to fit the center rivet, where the mesh is attached to the bars. We got the pool noodles at the dollar store nearby for less than $10 and since ... full review