For much of the 1980's and 1990's, federal transfer tax rates, exemptions, and credits were static and easy to remember. Then the roller coaster changes started. I don't know about you, but the number of changes has exceeded my capacity to remember them all. I've kept a cheat sheet under the glass of my desk for a few years. I have now expanded and updated it, and thought it would be worthwhile to put it out there for others. You can download a copy of the table from here.
For other helpful tables and charts, take a look at the links in the column on the right.