The most useful/useless APs to take

I was going to have a surprise for you all, but I thought it would be better to leave it for another day (yes, it is already done but just thought that we should let some time lapse before showing it)

Anyway, as the title says, if you are debating whether or not some AP tests are worth the money and time, I have written up a list here of all the APs that our school students take and how useful they are.

My criteria is very arbitrary, but I take into account the following factors:
1. Usefulness of content in the long run
2. Ability to get it recognized (in terms of college credit)
3. Prevalence (if everyone has it then the need to take it increases?)

I make certain assumptions, namely:
1. You intend to go to a US school
2. The policy at Stanford will be representative of other schools (I did not have the time to go to every school and check their AP policy)

Before I start though I want to make certain statements about the APs. As with all posts bear in mind this is just my opinion.
1. Content difference. In terms of depth, APs cover a lot less material than A levels for certain subjects (e.g. chemistry), and sometimes different emphasis in material (e.g ap bio). If NUSHS is still tailoring the curriculum just so that you can do well in APs then please bear in mind that you are losing out to your A level counterparts in terms of content.
2. Usefulness. In terms of number of credits you get in university, A levels allow you to get twice the number of credits (i.e 1 year worth) while APs only allow you to get 1 semester's worth.
3. It's contradictory to the previous statement, but in US schools you can get credit for AP chinese but not O level Higher Chinese. [i dont know about A level chinese, does anyone know?]
4. More people know about the APs than A levels in the US.

Now for the rankings:
1. Calculus BC / AB: Extremely useful in sciences and social science (such as economics). Calculus is a pre-requisite for so many subjects that having a calc ab/bc grade will definitely allow you to skip some courses.
2. Physics C: Extremely useful if you want to do engineering / physics-related stuff, definitely allows you to skip courses
The rest fall way behind.
3. Statistics: Stanford does not offer credit for this AP, but the content in AP stats is immensely helpful for someone doing social science like me (we are required to take stats classes and they cover the same material as AP stats). The practice questions that you do from the preparation for the AP test helps you cope very well when you need to recall all that info again.
4. Chemistry: Only useful if you want to do chemistry, if not dont bother
5. Bio: Useful content, but credit not recognized in Stanford. Ranks above physics B because if you ever go on wilderness trips at least you can talk about the flora and fauna with the AP bio knowledge. [I never regretted taking it just cos of this reason]
6. Physics B: Allows you to skip some classes in physics as well, but if you intend to do physics-related stuff in uni chances are you are already doing physics C.