Inflatables have a built-in fan that keeps them inflated while plugged in, and most have internal LED lights for a glow at night. Sizes range from about 4 ft to 12 ft or more. Measure your yard and think about sightlines: a 6 to 8 ft inflatable reads well from the street on most lots.
Wind is the main enemy. Good inflatables include ground stakes and tether ropes; use all of them. Many owners switch inflatables off during storms or strong wind, which also protects the fan.
Look at the fabric and seams. Thicker polyester with reinforced seams lasts more seasons, and a waterproof fan housing is essential. Some newer models include projectors or animated parts, which add cost and more things that can fail. Store them dry and loosely folded after the season.
Put inflatables on a timer so they inflate at dusk, and leave room to walk around them. Mix them with lighted yard decorations for a balanced display.