The best thing you can do is take the number of AP classes that you feel comfortable excelling in. You should plan on getting an A in each AP class you take, other wise it doesn't benefit you that much as far as college admissions go. A good idea would be to take all of the AP classes offered in your strong areas. For example, if you excel at math, try to take the Calculus AB and BC exams (take the BC exam if you only want to do one), and any other math APs that your high school offers. This communicates to the colleges you're applying to that you challenge yourself in areas of interest and can succeed in those areas.

In my opinion, it's a bad idea to take every AP class your high school offers. If your school offers a good variety of AP classes, then it may really be difficult for you to take a full schedule of them and still succeed in all of them. You may spread yourself too thin, and end up with mediocre grades. This means that while your schedule will look very difficult, the admissions department may be unsure of your ability to succeed under pressure because your GPA and AP class grades will be a little lower.

In general, you should take as many APs as you can safely handle. The workload for AP classes is definitely larger, so it's important to be selective when choosing which AP classes to take. You should also try to spread them out so you're not taking a full schedule of AP classes your senior year. Good students who are willing to work hard are generally okay with half of their classes being APs at my school.

I disagree with what soccerbabe said. You can't just pile college credit on top of college credit as a result of AP scores. All schools have a limit to how much course credit you can receive from APs, and it's usually not that many. Also, some schools won't give specific course credit for APs, they just give general elective credit. Many students getting in to schools these days have more AP credit than the college will accept.

I would suggest taking as many as your school offers, if you can handle it. AP classes not only improve your GPA, but also improve the difficulty of your schedule. I've heard admissions departments place a lot of importance on the difficulty of your class schedule because it shows you have the motivation to challenge yourself. They place special importance on receiving good grades in AP classes because it means you can challenge yourself and succeed at that challenge. If a college sees that you took every AP class that your school offers, they'll know that you're a very motivated student.

In addition, the more AP tests you take, the more college credit you can receive for the scores.

I think it really depends on the type of APs you select. You should want to take a course that you know you will benefit from for the major you decide to take in college. Your main goal in picking AP classes is to be sure you pick the right ones, and be sure you know these classes will help in future. And don't bog your self down with APs, because you'll have barely any social time, which is much needed, especially since you'll be bogged down with more work in college anyways.

As many as you can. At lest 2.

Colleges don't want students to take all the AP classes they can because they think it will help them get into college. However, they also don't want to see that you are taking really easy classes either. Just take classes where you feel challenged in but don't take too many so that you are drowning in homework every night. Keep in mind that if you do enroll in an AP class, you have to take the AP exam in May and colleges usually accept scores of 3 and higher.

I think you shold take as many as you can.......depending on your grades.

On this site everyone loves giving long answers but I'll give you a short and simple one.

Take as many as you think you can handle.

Only take the AP classes that suits you. Having a failing grade or maybe even a C on an AP class will look very bad. Don't overdue it, but also challenge yourself. It will look better if you take as many AP classes as you can, but only to make an A or B+ in it.

Take as many AP classes as you wish, but make sure you can handle them.
You don't want to overload yourself.
Take AP in classes that you know you will do fine in, for sure.
And if you are really confident, then take AP in other classes that you don't do as well in also. It will be a challenge but you can handle it if you try!