To Eat or Not to Eat
One of the classic questions regarding the holiday of Chanukah is whether there is a mitzvah to have a festive meal or not. One would wonder: Why is there a machloket (halachic dispute) about whether to have a festive meal or not? Is there a special occasion in the Jewish calendar that doesn't have a meal attached to it? When in doubt, eat!
The Shulchan Aruch rules in accordance with the Tur, who quotes the Maharam of Rotenberg, stating that the Rabbis did not include festive meals as part of the celebration of Chanukah. Therefore, the increased meals one has during the holiday are optional (not a mitzvah).
The Rema comments on this ruling, citing an opinion that maintains that there is a partial mitzvah to have festive meals during Chanukah because during the days of Chanukah the Altar of the Beit Hamikdash was rededicated. He concludes this point by stating that the custom is to sing songs of praise at the festive meals, thereby seemingly making the meals a mitzvah according to all opinions. A difference, however, still remains between the two opinions. According to the Maharam of Rotenberg, though the meal becomes a mitzvah, it remains optional, while according to the other opinion, which is based on a Midrash, festive meals are part of the holiday. (Shulchan Aruch Orach Chaim 670)
The Ben Ish Chai writes that one should increase the Shabbat meals of Chanukah in order to publicize the miracle, more than during other weeks, especially if Shabbat falls out on Rosh Chodesh Tevet.
The Levush explains that a festive meal was not included in the celebration of Chanukah because the Greeks didn't really want to kill our ancestors, but, rather, they wanted the Jewish People to be like them. It was only because a group of “stubborn Jews” began to fight back that things got violent.
In closing, don't forget to enjoy the donuts (“sufganiyot” here in Israel). If a person is eating them during a meal with bread, he does not say the mezonot blessing on them.