Love your neighbor: R' Levi Yitzchak m'Berditchev - we love ourselves even though we're not perfect, we should love others even with all their faults.
נחלת צבי: Why does the Torah say "ואת שבתותי תשמרו" using the plural? Rashi says that the Torah juxtaposes honoring one's parents to Shabbos to teach that one shouldn't listen to one's parents if they say to violate Shabbos - we know that already; why doesn't he make this drasha in the Aseret Hadibrot where they are also juxtaposed?
רבינו בחיי: Why did the Torah specify אריכות ימים for honoring parents? The Sefer HaIkarim and the Ktav Sofer provide a reason for כיבוד אב ואם beyond simple הכרת הטוב - connection to our mesorah.
Ramban: The mitzvah of tochacha is a סייג לתורה put in place by the Torah itself to prevent coming to hatred