There's always the self-proving handwritten will, but I can see where that could go badly, quickly.
Thanks to the lawyers, any will can go badly now. Once you're dead, you have no say so. If there's a possibility of a contest, best to give away your stuff while you're alive. You can give individuals each $13,000/year without tax consequences. Properties & investments can be given away in any amount with no tax consequence until it's sold, but since the cost basis to the seller is zero, they'll have a hefty capital gains tax on the way out.
Plus you get the satisfaction of knowing your wishes were respected.