What is the highest form or vehicle of Buddhism ?

Answer 1

That is a matter of opinion.

My opinion is that Zen Buddhism, practiced as intended, is the highest form of Buddhism.

What do you mean by vehicle?

Answer 2

A concise answer to your question as to which vehicle of Buddhism is the highest form is "none," depending on what you mean by "highest."
An expanded answer is below. Although this answer is expanded, it is not definitive. This question should be asked of a respected and qualified Buddhist teacher who can expand it much further.

The Vehicle in Buddhism refers to method.

There are two main vehicles called the lesser or smaller (Hinayana) and the greater or larger (Mahayana). The greater/larger vehicle is also divided into two branches that are also called vehicles. The terms lesser and greater refers to their relative paths. This means that they involve a lesser or a greater number of people.

In the lesser vehicle a person practises to liberate themselves. There is a concentration on a person's own development.
In the greater vehicle, the emphasis is on all beings, that true liberation is only possible when all beings without exception are liberated. This is especially so since it is intolerable for those close to being liberated to bear even the thought of others suffering, and so they sincerely wish and work for all others to be liberated.

The analogy often used is of a small boat (vehicle) that can hold one person or a large boat (vehicle) with many passengers.
An important point is that there is not a value judgement in the terms lesser/smaller and greater/larger both are efficacious. Both a large and a small boat can efficiently cross a body of water. In fact, it is not really possible to practise the greater vehicle without having first practised the lesser vehicle. One develops altruism as a result of having cultivated sensitivity.

The greater/larger (Mahayana) is also divided into two "vehicles," or methods. There is a vehicle based on the recitation and contemplation of scripture (Sutra) and a vehicle which also relies on an orally transmitted tradition (Mantra). These two are referred to as Sutrayana and Mantrayana. Mantrayana is also called Tantrayana or Vajrayana.

While there are these different vehicles, it is very important not to consider one as "higher" in the sense of better, since they are all considered to be effective means for liberation, and no means to liberate beings should ever be belittled.

Answer 3

There are three vehicles in Buddhism. The hinayana, mahayana and vajrayana. Vajrayana is considered the highest vehicle.

Answer 4

My guess is the Bodhisattva, who is a person that refuses to enter Nirvana until all others have gone ahead of him or her.

Answer 5

The lowly and humble fart.

Answer 6

http://www.buddhanet.net/

Blessings )O(