Bad adviser? No brainer: Use SDN, even with the high angst levels. Pay special attention to gonnif,
LizzyM, gyngyn, QofQuimica, Catalystic, WingedScapula and Mimelim, cabinbuilder, DoktorMom, Mad Jack just to name a few of the very wise people here.
For bad professors, this is a good training for bad med school faculty. Yes, med schools have bad teachers too. I have a few colleagues who are wonderful people, outstanding scientists, great colleagues, but they simply can't teach their way out of a paper bag, and their student evaluations reflect this year after year.
So, what does one do? You become a good self-learner. Chat up your classmates who are doing well (not everyone will be a gunner), and seek out other faculty who teach the same subject. Depending upon the subject, use online resources like Khan Academy. For my subject alone, I can find numerous YouTube videos. Go talk to to the Professor or TAs. Be in their office constantly if they're not clear on things.
This is a common question that has come up time and again from people I tutor, and I have wondered about the "best" solution myself... The easiest thing to do is just to suffer in silence or to move to a different class or adviser (if allowed to and some people are NOT allowed to do so without taking action). The most socially responsible thing to do would be to take action toward solving the problem so that other students might fare better. The biggest fear or risk is probably having a situation like this result in enemies, misunderstandings, or work it's way into an LoR somehow.
Has anyone had a very bad teacher or adviser, and how would you recommend handling such issues?