Testbug's speed tests
Note: with all these tests it's a good idea to click "Execute" a few times to try to iron out discrepancies caused by disk activity, processor timing allocation or cache management.
These tests are intended as a comparison of the speed of different coding on the same machine. They cannot be used to compare the speeds of different machines, since the tick periods for the performance counter which is used for these tests will vary greatly between machines.
I simply added speed tests which interested me at the time. If you would be interested in other speed tests, please let me know. and I might add them if I find the time.

Comparing basic coding
Stack movement speeds
   PUSH, POP and direct read

Optimisation tests
   LOOP v DEC ECX, JZ ..
   REP v DEC ECX, JNZ ..
   Alignment of oft-called functions
   Alignment for memory reads, writes and compares
   Conditional jump branch hints

FPU v CPU speeds @ 64 bits
Data in code section

Comparing ASM and other functions
Writing decimal
Writing hex

Comparing Win32 APIs
Memory heap
Drawing text