For real home defense, a lot of people are now using the new "reduced recoil" buckshot loads.
These have less recoil but are still as effective as full power loads.
The lower recoil allows you to shoot faster, since you're not being rocked and battered by the heavy loads.
This is available from most makers, and is usually in either #00 or #4.
For standard loads, go with your choice of #00, #4, or a good compromise, #1.
Stay away from Magnum loads and bird shot.
Magnum loads are for hunting game and have HEAVY recoil.
Bird shot is for birds. It lacks the ability to penetrate to vital organs.
