"Hayate no Gotoku", season two is definitely a graphical improvement on the first. I'm not saying that the animation from season 1 is bad, I'm just saying that the new animation is an upgrade from the original.
...Anyhow, the second season is more of the hilarious fun that we know and love. All the characters have returned with full force, bringing with them more aspects of their personalities which were seen in the manga version. A definite plus in my opinion.
This time the focus isn't set as much on Hayate's debt as it is the slight romace that goes on between the characters (though Hayate still isn't able to tell if a girl is hitting on him. Good ol' ignorant Hayate.) One of the characters that the season seems to focus on most is Hinagiku, and how she realizes a new fact about herself.
Also, this season does NOT pick up after episode 52 of season one. No, this season takes place right after episode 25, helping keep a stronger closeness to the manga.
(A.K.A. Null ALMOST all the episodes that take place after episode 25 of season one)
This series is one that I recommend to people young and old alike. If you like comedy, want a romance show, or just plain ol' want to watch something different yet familiar, this is a show for you.