Why did Yosef want his brothers to settle specifically in the land of Goshen?
Rashi: It contained ideal grazing-grounds for their vast amount of flocks.
Da'as Zekenim: Paro had given it to Sarah. This is why Yisrael desired it, and received it, and the Mitzriyim did not protest.
What made Yosef so sure that Par'oh would designate for them the land of Goshen?
Rashi: He was sure that, once Par'oh knew that shepherding was their sole area of expertise, he would settle them there, away from the main areas of Egypt, because the Egyptians, who worshipped sheep, despised the shepherds who looked after them. 1
Rashbam, Da'as Zekenim #1: The Mitzriyim despised shepherds who raise Tzon, which they considered disgusting.
Abarvenel, Sifsei Chachamim: They consider shepherds holy, and will settle them in the best part of Mitzrayim.
Both Targum Onkelos and Targum Yonasan translate "To'avas ... " as they kept their distance from them. Riva, Hadar Zekenim - they despise shepherds, for they hit the flock with sticks. Riva - also, they know that shepherds know that there is nothing [divine] about Tzon. Also, they benefit from the Tzon; they drink the milk and use the wool. Some say that it is because they eat them (Hadar Zekenim, Da'as Zekenim #2). Riva - the verse connotes unlike this.
How could Yosef cause his brothers to be despised in the eyes of the Egyptians?
Oznayim la'Torah: Better to be despised in the eyes of the Egyptians 1 than to live together with the wicked Egyptians and to be contaminated by them!
How can it be that the Egyptians despised shepherds? We find that they had flocks in Makas Dever, and Paro had flocks!
Moshav Zekenim: They would not allow flocks near them, only far away, in the field.