见解：对事物的认识和看法。 观点：从一定的立场或角度出发，对事物或问题所持的看法。 见地:见识，见解。 看法：对事物的认识和见解。 意见：见解，主张；对人对事不满意的想法。 想法：动词是设法的意思，名词是思索出来的结果,念头，点子。 顺便加上另一个词语，见识：见解，知识。主意，计策。接触事物，扩大见闻。 可以说它们都是同义词。

观点，侧重对时事和新事物的看法，多用于新闻评论等场合。（opinion on current affairs） 见地，强调看法高出一般人的理解，更深刻专业，多形容专业人士的看法。(professional opinion) 见解，跟看法基本一样，更加书面化。( written word) 想法，侧重说明思考某种方法去做或者去解决问题。(think a way (to do sth)) 意见，跟看法基本一样，多用于官方用语，或者正式场合用语。(official /formal) 看法，比较口语化的opinion。(casual)

It's so complicated that the meanings of these words depend on the contexts. All the words have the meaning of idea, opinion, or view etc, and also have the meaning of sb's attitude towards sth, especially for the words "意见",“看法”, and “想法” . When you can't recognize which word is suitable for your purpose, you would use "看法" or “ 想法” because they almost fit in any situation.

This is a good question.