I agree with John. The other words could also be used in some cases: Could is used when you are giving any idea- not as strong as should- "You could try this other website." Might can be used the same way, but not so much in American English- "You might try this other website." Would is often used to indirectly give advice by telling the person what you would do in their situation- "If I were you, I would try this other website." / "If I were you, I wouldn't call that girl."

Typically we use should. You should study more. You should eat healthier. You should talk to your father more often.

Usually 'should' is most commonly used for giving advice, or saying that someone really ought to do something (especially used when they have not asked for advice) You should try this cake, it's delicious! 'Could' is can also be used for giving advice, but has a lower modality (strength) than 'should', and is really more associated with suggesting than giving advice. We could go to the beach on Saturday. 'Would' is generally not used in this context, but you can still say something like... I would recommend the fish and chips. 'Might' can have a similar use in... You might like to try the fish and chips. hope I could help you! :)