Are there ayat to the effect of "be nice to others" in the Qur'an?

It's not hard to find examples of people saying Islam teaches people to be nice to others: > Islam places great emphasis on manners and on the proper way to deal with others, whether they are Muslims or not. -- Questions About Islam > > Thus, it is not permissible under any circumstances for Muslims to mistreat a non-Muslim who has not committed any aggression against them; they are not allowed to harm, threaten or terrorize him, steal his wealth, cheat him or deprive him of his rights. -- How are Muslims supposed to treat people of other faiths? My overall impression on reading the Qur'an was that it's quite important for Muslims to be nice to others (and I try to be nice to others [I don't always succeed, but you know...]). It's something I've experienced personally from other Muslims all over the world, and it's now something I assume (You're Muslim? That means you'll be nice to me.) and I mostly haven't been disappointed. However, I don't recall a precise ayah that means "be nice to others" in simple, general terms. **Question**: Are there ayat to the effect of "be nice to others" in the Qur'an?