Hanaukyou Maid-tai: La Verite

In both anime MC falls in love with his maid 

These two series are similar because they both have a harem setup. In Hayate, the male lead is a butler, but in Hanaukyou, the male lead is the master. In both anime, the male leads are new to mansions and servants, and there is a female maid who is two years older and a love interest of the male lead in both anime. They also both have comedy aspects. These anime are dissimilar though because Hayate is much longer and there is less romance than Maid-tai. Also, the harem aspect of Maid-tai is much greater. 

Both have maids and general harem around them, Maid-tai La verite however takes itself a little more seriously while He is my master is more light hearted, both are high levels of fanservice though. 

Its abit the same and abit different. some differences are noticeable and the story is more in-depth. just watch it to see the differences