<p>It really depends on your previous experience with subjects. Apart from the three “easy” ones to self-study for, many others are realistic if you’ve taken other classes. These are the exams I’ve self-studied for, or are currently self-studying for, using books, online courses, and through dual enrollment:</p>
<p>AP English Language (5): I self-studied it last year to skip a class at the CC where I dual enroll. If you’re a fairly good writer and self-disciplined enough to spend time on it, it’s not that difficult. I just memorized the rhetoric devices and did practice essays. </p>
<p>AP Calculus BC: I took it last year (dual enrollment) but will be taking the exam this year. If you’ve taken a regular calculus course, I think it’s doable. If not, it will be difficult…</p>
<p>AP US History: Also dual enrollment this year…if you’ve taken a regular US history course, or are very good at history, and are good a memorization, it’s definitely realistic. Make sure to spend time getting used to the essay format.</p>
<p>AP English Literature: Same as above, but replace history with literature. Very reading intensive, but I think it’s still a writing test…so…</p>
<p>AP Computer Science: I’m doing it through Amplify’s MOOC. I had a bit of previous programming experience with Python, but really, Amplify aims their course to beginners. I spend maybe 2h a week on it, and will start spending more getting used to the exam format.</p>
<p>AP Physics C: This one I don’t recommend, although I’m doing it, unless you’ve had a very good grasp of physics and calculus. I’m using prep books, online resources, and a textbook but it’s still tricky and stressful. </p>
<p>Other courses that I’ve heard are relatively easy to self-study, although it really depends on how good you’re at a given subject:
AP Gov, AP Econ, and AP Stat. I suppose the other history, science, or foreign language are all possible too. It really depends on how crazy you are. 
Good luck!</p>