While my first program was written in Basic, a simple game typed onto a neat roll of yellow paper tape during lunch hour, my first program as an engineer was written in assembly.  I still have nostalgia for the assembly language and it's ability to squeeze amazing performance out of even whimpy computers.  While the popularity of assembly language has dimished much over the years, you can still enjoy it and might even find good excuses to use it again.

Check out the Art of Assembly Language Programming and HLA (High-Level Assembly) site.  There you can find the latest version of the classic Art of Assembly book and assembly language tools/libraries.