Yes, I do. Just my opinion.
Penn was never really a proven top welterweight, he just had one single amazing win there (Hughes).
Hughes is historically a great fighter, but I'm not sure how good he really was h2h at the time GSP fought him.
And personally I think Shields looked like shit for the vast majority of his time in the UFC. Has a good overall record etc, but often fought like a mediocrity.
All of the above were VERY good wins mind you, I rate them all, but personally I consider Fitch and Condit his two greatest victories.
Both convincing wins over prime natural proven welterweight elites. Superb.