My favourite patches/hacky programs:
GigaMem 3.12 - Virtual memory on Amiga. Requires 68040 or better and an MMU
MCP 1.48 - The Master of patches
TLSFMem 1.6 - A better memory allocator for AmigaOS. Makes your system faster.
MagicMenu 2.35 - Nothing beats having your workbench menus anywhere. Transparency is also cool.
Oxyron patcher 3.14 - Patches some FPU instructions and speeds them up. Requires 68040 or better with an FPU.
DynamiCache 1.03 - Configurable drive cache for speedups.
Note: SaferPatches garbles some MovieShop gadgets. So I dont use it.