Depends on what you're going to do.
If you need this for personal reasons only (e.g. to test out webpages, test out some scripts) then PWS is a good enough choice (It only allows, if i'm not mistaken, maximum of 12 concurrent connections)
If you're planning on hosting several sites out to the public, run some scripts, php, etc. *And* want something that's more feature-set rich as well as fast/reliable then Apache for Win32 is definitely the way to go.