* Οικογένεια (Oikogeneia): This is the most common and generally accepted translation for "family" in the sense of a nuclear family (parents and children) or an extended family. This is probably what you'd want to use most of the time.
* Συγγενείς (Syggineis): This refers to relatives, family members, or kin. It's a broader term than οικογένεια.
* Φυλή (Fuli): This translates to "tribe" or "clan" and is used for a larger, more extended family group, sometimes with a shared ancestry. It's less common in everyday conversation about a typical family.
So, for most situations in *Friends*, οικογένεια (Oikogeneia) is your best bet.