Assalamu alaikum wa rahmatullahi wa barakatuhu!
In the Name of Allah, Most Gracious, Most Merciful
In terms of his lineage, the Prophet (saw) was the best, from the best - all the way back to his last forefather - Prophet Adam (as).
He (saw) was born to parents who did not fornicate, but who instead were married. His forefathers were leaders among people, chiefs of tribes and sub-tribes. Each one of them inherited noble qualities from his forefathers.
If you were to go back twenty years before the Prophet's (saw) birth, you would not find a man who possessed the noble qualities that the Prophet's (saw) grandfather, Abdul Mutallib, possessed.
And, if you went a number of years further back, you would not find a man who was nobler and better than the Prophet's (saw) great-grandfather, Hashim.
The same can be said about all of the Prophet's (saw) forefathers - Abd Manaf, Qusay, and every one of the Prophet's (saw) forefathers between Qusay and Adam (as).
May the peace and blessings of Allah be upon Muhammad, upon his family, and upon his Companions as long as stars appear in the sky, as long as birds continue to sing, and as long as the wind continues to blow - Ameen!