No remains specifically of Goliath or King Og have ever been found. Kurdish independent news reported this past July that skeletons of four men nearly 3 meters tall were found at Rizgari town in Sulaymaniyah province, Iraq. They were from 4,500 BC. 
Independent historical evidence from the Greeks, Egyptians, and Canaanites report the same giant tribes who lived in the land of Canaan during the time of the Hebrews in the Old testament.
The MFA news bulletin for July 8, 1994 reported that the skeleton of a 2 meters tall man was found in Israel, near Atlit in a 6,000 year old Neolithic underwater grave.
In 1979 a 1st century tomb discovered in Jericho had an ossuary with the name "Goliath" inscribed. The skeletal remains indicated a man 1.9metres tall (6 feet 3 inches). "Goliath" here was not a personal name but a nickname.
Archaeological excavation of Gath started in 1996. Only a handful of skeletons of Philistines have been found, all normal-sized. However, in 2005 Archaeologist Aren Maeir found a pottery shard with the name "Goliath" inscribed on it at Tel es Safi -Gath. It dated to the 10th century BC, the same era as Goliath. Another shard from Gath had the name "R'pa" or Rapha inscribed on the back.
In 1902 Irish archaeologist Robert Macalister (1850-1930) found several large skeletons almost 2 metres tall at Gezer, 6km south of Gath and 30km west of Jerusalem. Gezer was near the border with Israel but still in Philistine territory.
A papyrus Anastasi I, written by Hori, an Egyptian scribe, about 1200 BC warned travellers of "Shasu" giants 4 -5 cubits tall ( 7 to 9 ft) who lived south of Megiddo in Canaan.
A seal impression found at Megiddo has an engraving of a very tall man having his head cut off with a sword.
Inside the Abu Simbel Temple of Ramesses II in Egypt is a relief of an Egyptian soldier guarding "Shasu" prisoners in Syria, two of them are huge.
The Bible speaks of a tribe called Rephaim noted for its big soldiers. Indeed, the word "giant" is translated from Rephaim and it's sometimes ambiguous whether "Rephaim" refers to the tribe or to size.
"Og king of Bashan" described as the "remnant of the Rephaim". (Deuteronmy 3:6-11) Bashan was a large area east and south east of the Sea of Galilee. King Og, it's implied, was a huge man – his bed was 9 cubits, or 13 feet long. (Deuteronomy 3:8-11) The phrase "remnant of the Rephaim" refers to a remnant north-east of the Dead Sea since other Repahaim lived west of the River Jordan (Joshua 17:14-18) and survived for centuries.
In 1928, the Ras Shamra Texts were found on the site of the ancient city of Ugarit (located in Syria). The cuneiform tablets date to 1200 BC. These speak of the existence of "R'pum" (Rephaim) kings and mighty men who worshiped at Ashtaroth and Edrei, in the land of Bashan, confirming the existence of the Rephaim people precisely in the land of Bashan.
When the Philistines arrived, the western Rephaim became their allies.
In 1985 Jonathan Tubb, curator for Syria/Palestine in the British Museum, commenced the excavation of Tell es-Saidiyeh near the southern border of ancient Bashan. Among the finds were seven unusually tall skeletons from about 1200 BC, the tallest 1.95 metres.
The Bible also speaks of the "Anakim" who lived in Canaan. The Israelite spies described them as, "greater and taller than we". (Deuteronomy 1:28; Numbers 13:30-33)
The Egyptian Execration Texts (composed between 1900 - 1700 BC) are a collection of Egyptian records. Interestingly enough, they refer to the "ly-Aneq" people of central Canaan.
Alcaeus of Lesbos circa 600 BC mentions the killing of a giant at Ashqelon, in Philistia who was 4 Royal Babylonian cubits and 1 span tall -- or 8 feet. Pliny, a 1st Century historian, testifies that a 9 foot 9 inch high giant named Gabbaras commanded one of the Roman legions (Legion Adiutrix). The 1st century AD historian Flavius Jospehus mentions a man named Eleazar who was sent as a prionser to Rome, his height being 7 cubits, or over 10 feet.
Giant people 7 to 9 feet tall have been recorded in modern times  and some ancient bones have been found of even taller people, the size of King Og .
For a good scholarly article on the real height of the Giants of the Bible Prof. Clyde Billington Ph.D of Northwestern College Minnesota has written an article entitled: "Goliath and the Exodus Giants: How Tall Were They?”