Unless you are quite affluent, the widow (and unmarried daughters) are likely to get everything. For middle class people, the wife’s kesubah (which by halacha is a lien on the husband’s property, rather than a share of the estate) is probably greater than the net worth of the estate.
I doubt anyone would include government insurance and pensions (such as social security and anything you receive covered by ERISA) as part of the estate. Houses are trickier since land belongs to the crown, and all you own are rights to live on it conditioned on following their rules (which in America translates into a rule that the widow gets clear ownership of the house if you bought it jointly – and since it is the state that is granting you the right to the land, Dina Malchusa probably applies).
Also remember that by halacha the sons inherit subject to a requirement to support the mother (American law allows kid to dump their parents on welfare and walk away, halacha doesn’t), so if the mother is alive, the sons are, to use legalese, receiving the estate subject to a condition.