Wikipedia’s got it so wrong…
This is what I hate about Wikipedia's markup...
''italic''
'''bold'''
'''''bold italic'''''
What kind of stupid markup uses six characters to indicate a simple style change that is used often? Yet it has no markup for CODE so you're stuck using HTML for something that can be fairly common for some communities.
Too many of the markup languages create markup that is harder on the user to make it easier on the programmer. (Because the markup was invented by the programmer, of course.) That's one thing I really applaud TWiki for... the code bends over backwards (and I know, because I've studied and modified that code) to make the markup simple for the user.
Just as annoying is TikiWiki's CODE markup... -+code+-. Darn pain in the butt to type, and I'm typing it all the time in documentation at work.