With an assist from Wikipedia...
List of Elected Heads of State
President - United States, France, Germany, many others... (alternatively, Federal President in Austria)
Chairman of the Presidency - Bosnia. Here there are three heads of state (one Bosnian, one Serbian, one Croatian). They are elected together to 4 year terms, and the one with the most votes becomes chairman. However, the chair rotates every 8 months, so everyone gets to ride.
Yang di-Pertuan Agong - Malaysia. Means literally 'He Who Was Made Lord,' and is the elected monarch of Malaysia. Nine of the 13 Malaysian states have hereditary local rulers. From among them, a Yang di-Pertuan Agong is elected every 5 years. I suppose you could use any other name for a King or Queen here as well. After all, they elected their monarchs on Naboo.
Supreme Leader - North Korea. The previous Kims were technically elected. However, Kim Jong-un has not yet been elected; there was supposed to be an election last year. I don't think anyone was surprised when it didn't happen.
Sovereign - Vatican City. The pope is elected, and in his capacity as the head of state (and absolute dictator, really) of the Vatican, his title is Sovereign.
Captain Regent - San Marino. Two are elected twice a year. Also serve as heads of government.
Note: Pretty much everyone has a President these days
List of Elected Heads of Government
Prime Minister - UK, Russia, Canada, Japan, many others. This is the most common name.
President - United States, Brazil, Mexico, Indonesia, others. In many countries there is no distinction between head of state and head of government.
Chief Executive Officer - Afghanistan. Also valid when mega-corporations become sovereign in a dystopian future.
Chancellor - Germany, and Federal Chancellor in Austria.
Chairman of the Council of Ministers - Bosnia.
Premier - Taiwan, China (if it counts), Niue. The Taiwanese head of government is also called the President of the Executive Yuan. Yuan means court, best I can tell.
Head of Government - Morocco, Tunisia. Booooring.
Federal Councilor - Switzerland. The Swiss have a seven member group with a President and Vice-President that acts as a collective Head of State and Head of Government. Since the senior member is the President, I didn't mention this in the Heads of State Section. There is also a Federal Chancellor who is a sort of Chief of Staff of the the federal bureacracy. Wikipedia insists that the Federal Chancellor is not a 'member of the government,' but I know duck when it quacks.
Captain Regent - San Marino.
Taoiseach - Irish. The Irish gotta be different.
Ambiguous titles from the Ancient World
Consul - Ancient Rome. Two were elected for one year terms. This is a little more confusing, since there were two consuls and multiple Praetors who all had imperium, the right to command armies, which is normally a thing associated with only a Head of State nowadays. To make it even more confusing, another official, the Censor was held in higher dignitity than the Consuls, yet had no imperium. I would say that if an Ancient Roman republican government were operating today, the Censor would be the head of state an the Consuls would be heads of government. The real power of the Consulship was that it was a pathway to the Senate, which was the dominant power in the legislature-first Roman republic.
Dictator - Ancient Rome. Ironically, the dictator was originally elected to a limited term to deal with a military emergency.
Tyrant - Ancient Greece. Also ironic, the Tyrants were usually (though not always) elected. I mean, Hitler was elected too, so I guess its not that ironic.
Archon - Ancient Greece. This is another confusing title, as there were usually multiple Archons in a given city-state. The Archon Eponymous was the chief Magistrate in Athens, while the Polemarch (senior to him) was the head of the army and the Archon Basileus was the most senior Archon, and something like a head of state. As with Rome, the real power of the Archons in Athens was admittance for life into the Areopagus, a Senatorial body which held most of the power from ~680-580 BC. There were too many variations of government both over time and between city state to mention here...
Ephors - Sparta. ...except for the Athenian's ancient rivals! How can we not mention them. Sparta had two kings, but also had five ephors. Again, its hard to tell exactly who was head of state and who was head of government. According the Plato, the ephors had the real power, while the Kings were glorified generals. I'm sure it shifted through time.