Buy the biggest and best safe you can afford and make sure it's anchored to the floor and wall.
With the lower end safes(under 3k) the way they get into them...is knocking them down on their backs so they have leverage to open.
There are hundreds of videos on this on YouTube. A second safe is a good ruse, but remember, tell nobody about it. Half the battle is opsec. If you have kids, make sure they don't tell their friends.
Any safe can be opened, all you are doing is slowing them down..buying time. They want to be in and out as fast as they can. The harder you make it for them and the longer it takes, the better the chance they give up.