Which open document format?

I like html myself... I just got into it with a prof that refused to
hand out a sylabus in class but posted it in .doc.

This would have been fine except for two things
1. A picture showing how to format homework did not work with the msft
viewer or oo.
2. The printing format was all screwed up and no one could get it to
print without messign up the tables.

I ended up bugging the guy to put it up in html and all the problems
were solved.