What should be better to Hashem?
Rashi: My Tefilah.
Radak #1: My song of praise to Hashem.
Radak #2: The Todah mentioned in verse 31, i.e. verbal thanks.
Malbim: My praise of Hashem will be better in His eyes than the bull that I will offer for a Todah, which has horns and a hoof.
Why does it say "mi'Shor Par"?
Rashi (from Rosh Hashanah 26a): It is the ox that Adam ha'Rishon offered - it was created in its adult height. The day that it was called a Shor, he offered it. A one-day old is called a Shor - "Shor
Why is it written Makran, and we pronounce it Makrin?
Radak, citing Shabbos 28b: The Kesiv hints to only one horn. Adam ha'Rishon offered a bull (refer to 69:32:2:1) with one horn.
What do we learn from "Makrin Mafris"?
Rashi: Its horns preceded Parsosav (its hooves). It was created in its height, and its head emerged first from the ground, the way all are born (head first).
Radak: This refers to Par, which has horns and strong hooves. Before it has horns, its hooves are soft. Before this, it is not Kosher for a Korban. The Par mentioned in the Torah for a Korban must be three years old.