93		Ultima Online: Renaissance (Windows, 2000)
91		Ultima Online: Third Dawn (Windows, 2001)
72		Warhammer Online: Age of Reckoning (Windows, 2008)
71		RuneScape (Windows, 2001)
69		Pagan: Ultima VIII (DOS, 1994)
68		Ultima VII: Part Two - Serpent Isle (DOS, 1993)
67		Ultima VII: The Black Gate (DOS, 1992)
61		Ragnarök Online (Windows, 2002)
50		EverQuest (Windows, 1999)
49		World of WarCraft (Windows, 2004)
46		Tibia (Windows, 1997)
45		Meridian 59 (Windows, 1996)
44		Dark Age of Camelot (Windows, 2001)
43		Guild Wars 2 (Windows, 2012)
43		Guild Wars (Windows, 2005)
42		Atlantica Online (Windows, 2008)
42		Asheron's Call 2: Fallen Kings (Windows, 2002)
42		MapleStory (Windows, 2006)
42		Yohoho! Puzzle Pirates (Windows, 2005)
42		Age of Conan: Hyborian Adventures (Windows, 2008)
42		EverQuest II (Windows, 2004)
41		Aion (Windows, 2009)
40		Club Penguin Island (Windows, 2018)
40		Albion Online (Windows, 2018)
40		A Chinese Ghost Story Online (Windows, 2012)
40		Wonderland Online (Windows, 2006)
40		The Saga of Ryzom (Windows, 2004)
40		Villagers & Heroes of a Mystical Land (Windows, 2011)

Notes: Games similar to Ultima Online, Games like Ultima Online, ORIGIN Systems, Inc., Electronic Arts, Inc., Windows, Role-Playing, RPG, Fantasy, Massively Multiplayer, Persistent, Bird's-eye view, Isometric, Ultima, PC, Game Similarities.