In the incipient phase drugs are not used very much, only if it's absolutely necessary. In this case the drugs used will be specifically targeted on the affected organ, trying not to affect the nearby tissues. But if the cancer has started spreading to other organs and to the lymph nodes in the nearby areas, the treatment will be more aggressive and systemic, that is the drugs will try to kill all the cancer cells in the patient's body. The drugs will be more powerful and that is why the patients have a hard time during chemotherapy, having side effects like nausea, vomiting, hair loss and a general bad condition.

Usually the drugs are given under the form of pills because they are better tolarated by their body this way. But they might also be given as liquids in intramuscular or intravenous injections. Once the patient has reached the terminal phase of cancer the drug treatment no longer focuses on the killing of cancer cells, but on keeping them alive as much as possible and also conforting them and releaving the pain. In this pahse the drugs are mainly very strong painkillers because once the cancer hits other organs it will start to be really painful.
Of course that all cancer patients want the best drugs used in cancer treatment, no matter what is their stage and the type of cancer they have. But the drugs prescribed differ from one person to another because patients react in a different way to them. The treatment is actually a drug cocktail, a combination of drugs that try to cover all bases and get the best results for the patient. Any way, these drugs change all the time because cancer research is advancing rapidly and new better medicines appear on the market all the time.

There are also new medicines being tested all the times during the clinical trials and some doctors recommend their patients to take part in these trials. Some of the breast cancer drugs may contain hormone inhibitors, so you see these drugs are all very different and there are lots of them on the market.
Here are some links to lists of the best drugs used in cancer treatment: www.cancer.gov, www.virtualcancercentre.com, www.chemocare.com, www.cancerhelp.co.uk. Of course the lists are only partial and some medicines may be known under other names in different countries, but the best drugs are the ones prescribed by your oncologist after running some tests because they are the best drugs for you, for your particular case.