Ibuprofen is a non-steroidal anti-inflammatory. The painkilling effects of ibuprofen take effect immediately, however the anti-inflammatory effects can take as long as a week.
Paracetamol (or acetaminophen as it is known in the US) is classified as a mild analgesic. It suppresses the feeling of pain, but does little to treat the cause.
Studies have shown that caffeine can boost the effectiveness of many analgesics, resulting in better, faster acting pain relief.
Codeine is an opiate used to treat mild to moderate pain. Opiates can alter the mood, sometimes resulting in feelings of euphoria. This can be beneficial for pain relief, however it can become addictive and withdrawal symptoms are common.
Aspirin can be used as an analgesic, antipyretic and anti-inflammatory.
Naproxen is an anti-inflammatory which can be used to treat a variety of symptoms of pain.