There are many fun 3D online games that can be referred to as the following popular types: 1. RPG: This type of game usually provides a rich story and character setting. Players can choose different characters and classes to explore, fight, and complete missions in the game. 2. Competition games: These games usually have arenas, ranking matches, and other playstyles. Players can compete with other players to improve their skills and results. Shooting games: These games usually have complex maps and weapon systems. Players need to use a variety of weapons to shoot and defeat enemies. 4. Action games: These games usually have fast-paced battles and complex action scenes. Players need to react quickly and accurately. 5-player online combat competitive game (MOBA): This type of game usually has multiple players forming different teams for real-time battles, including League of Legends, DOTA 2, etc. These are some of the more popular 3D online games. Of course, there are many other types of games that you can choose according to your preferences and needs.