I believe that speaking 'their language of love' is the best way to make a partner happy - with emphasis on the word 'their'. Your love for your partner or spouse can be conveyed in many ways but unless it's 'their' way, it doesn't have much impact.
Let's take an example. The husband shows love through physical intimacy, but the wife would rather have a kind word or an attentive ear at the end of a trying day. The love is there but it's not being transmitted through the proper medium - to put it clinically.
Learn the different languages of love and try matching your spouse's language with your own. It will make a huge difference in your relationship and you'll be amazed at how happy it can make your partner.
Do this just once and see the power of love languages at work!