It's described by Rambam as "the foundation of foundations and the pillar of wisdoms..."
What is the Knowledge of G-d's existence?
Men must wear these each weekday.
What are Tefillin?
According to Torah law, men and women must eat it on the first night of Pesach, even nowadays.
What is Matza?
If you refuse to redeem your firstborn donkey, you do this to it.
What is break its neck?
The "Sefer haMitzvos" was written by him.
Who is Rambam?
This mitzva is the mechayev of acts of kindness, and according to Rambam, all good midos.
What is v'halchta b'drachav ("Walking in G-d's ways")?
Although we say Birkas haMazon every time we eat a kzayis of bread, according to the Torah you only have to if you are in this state.
What is satisfied?
According to the basic law, nine of these should suffice; we must have thirty, and the custom is to do one hundred.
What are Shofar blasts on Rosh hashana?
If you come across a bird's nest, you might be able to do it.
What is Shiluach haKein?
This is a very popular book of Mitzvos, presented according to Parsha.
What is sefer haChinuch?
This mitzva is traditionally seen as having two forms: ___ of punishment, and ___ of awesomeness.
What is Fear (or Awe) of G-d?
This mitzva has two (or maybe three) berachos before it, and is described as being "worth all other mitzvos".
What is learning Torah?
To be happy on Yom Tov is a mitzva; therefore, men drink wine, and women must...
What is receive new clothes?
To do this mitzva, you'd have to be on a Beis Din, addressing a case of fire damages.
What is the mitzva to judge fire-damage cases as per the Torah's laws?
He wrote extensive critiques on the Rambam's presentation of Mitzvos.
Who is Ramban?
According to Rambam, we are to come to these mitzvos through contemplating the wisdom of G-d apparent in the Universe (2).
What is love and fear of G-d?
Ideally, when approached by a poor person, one must give him this much tzedaka.
What is All that he lacks?
It's very much like the issur to do melacha on Shabbos, except it's a mitzva.
What is resting on Shabbos?
Other than Rosh haShana, Yovel, and in the Beis Hamikdash, this is the only other time we are commanded to blow the Shofar.
What is a time of trouble (eis tzara)?
It's a type of poem which lists the mitzvos.
What are Azharos?
The Rambam states that one should remember this "tamid" (constantly). Others understand that once a year or less suffices.
What are the actions of Amalek?
It's the only mitzva which can only be done if one is sitting.
What is standing up for an elder or Talmid Chacham (kima v'hiddur)?
Some Rishonim hold there is a mitzva to do this on Yom Kippur specifically, although it applies year-round too.
What is Teshuva?
It's a mitzva on every Jew to listen to him or her.
What is a Navi?
This sefer, by R' Eliezer Azkiri, collects all of the mitzvos cited and listed in earlier seforim.
What is Sefer Chareidim?