Some assets, such as insurance and RRSPs pass to the beneficiary named in the policy or plan. Unless the named beneficiary is you, or your estate, these assets will usually pass directly to the named beneficiary and will not form part of the estate.
This is a common strategy for trying to reduce probate taxes, but unless
a) you are giving everything to your spouse, or
b) you have a well thought out plan,
it can be a mess.
Warning: taxes! unfairness!
Having assets pass directly to named beneficiaries is a common strategy for reducing probate taxes and executor fees. However, it is not without risk if the beneficiary is anyone other than your spouse who is also the principal beneficiary of your estate. It can result in some real unfairness. For instance, unless you roll your RRSP over to your spouse or disabled child, the entire value of your RRSP is brought into your income in the year of death and forms part of your taxable income in that year. This can result in you having a very high income and your estate having very high income tax payable. However, if the named beneficiary of the RRSP is not your estate, that individual will receive 100% of the RRSP without any deduction for the taxes payable. The liability for the tax will be borne by the estate (and thus the beneficiaries of the estate) and not at all by the beneficiary of the RRSP.