We've been using the XT30 connector in our starter kits for a long time now and they're excellent. Now with the constant development of smaller 3D printed balsters, these little connectors are growing even more popular.
They're super easy to solder to both 18 and 16AWG wire and are super compact. With a constant current draw of 30A, they are more than enough to handle even the beefiest of nerf motors.
Most LiPo batteries will not be fitted with XT30 connectors so choosing this type of connector for your blaster may require you to replace the battery connector also.
Price is for one connector.
Remember, male goes on the blaster, female goes on the battery.