* ή (í): This is the most common word for "or," used in most situations. It's a coordinating conjunction.
* είτε...είτε (íte...íte): This is used for a more emphatic "either...or." For example, "Either you go or I go" would be "Είτε εσύ πας είτε εγώ πάω (Eíte esý pas eíte egó páo)."
Therefore, the best translation of "or" in Greek is usually ή (í).