Dimension Pro has quite a few built in, Brandon Ryan used the rain and thunder sounds in one of the Cake TV videos. They were pretty good.
This has reminded me that somehow, over the years, 2x BBC Radiophonic Workshop sound effects CDs I used to own have gone missing :-( There was a large series of ~27 vinyl LPs released, e.g.
Unlucky for some! Fantastically ghoulish stuff like:
Arm Chopped Off (0:03)
Head Chopped Off (0:03)
Sawing Head Off (0:05)
Leg Chopped Off (0:02)
Neck Twisted And Broken (0:02)
Arm Broken (0:03)
Stake Driven Through Heart (0:04)
Branding Iron On Flesh (0:09)
Red Hot Poker Into Eye (0:07)
Nails Hammered Into Flesh (0:18) That poor cabbage..! :-(
However, one cabbage's misfortune is another man's good luck; because of this thread I've found one of the CDs on Amazon for about £3:
:-)