Here is the list of 6 top quality sci-fi MMORPG games, which you must find very interesting to play.

2. http://img3.wikia.nocookie.net/__cb20141024150000/warframe/images/b/b6/Archwing_Header.jpg

3. Explosive Features:
PvE co-op shooter.
Sleek futuristic environment.
Unique weapons and abilities.
Title: Warframe
Status: Released Graphics: 3D
Genre: MMOTPS
Developer: Digital Extreme
Publisher: Digital Extreme

4. http://static.tvtropes.org/pmwiki/pub/images/SWTOR_4325.jpg

5. Explosive Features:
Based on the popular Star Wars
universe
Fully Voice Acted Dialogue
Unique Class Specific Storylines
Title: Star Wars: The Old Republic
Status: Released Graphics: 3D
Genre: MMORPG
Developer: Bioware
Publisher: EA

6. http://cdn.akamai.steamstatic.com/steam/apps/99900/header.jpg?t=1409154168

7. Explosive Features:
Intuitive pick-up-and-play
controls
Console-style gameplay
Co-op mayhem
Title: Spiral Knights
Status: Released Graphics: 3D
Genre: MMORPG
Type: Browser
Developer: SEGA
Publisher: Three Rings

8. http://img09.deviantart.net/01ed/i/2013/085/5/6/scarlet_blade_cover_photo_mk_ii_by_blackace1
1094-d5zbq97.jpg

9. Explosive Features:
Interesting Classes
Large Scale PvP
Mech Suit Transformation
Title: Spiral Knights
Status: Released Graphics: 3D
Genre: MMORPG
Type: Browser
Developer: SEGA
Publisher: Three Rings

10. http://old.gamegrin.com/files/images/news/2013/RF_Online_Banner.jpg

11. Explosive Features:
Great PvP combat as well as RvR
Meticulous character building
Player-controlled politics
Title: RF Online
Status: Released Graphics: 3D
Genre: MMORPG
Developer: CCR Inc
Publisher: Games Campus

12. http://www11.onrpg.com/wp-content/uploads/2015/05/MetalReaper_668x227.jpg

13. Explosive Features:
Wide Variety of Game Modes
Mow Down Hordes of Enemies
Detailed Storylines
Title: Metal Reaper Online
Status: Beta Graphics: 3D
Genre: MMORPG
Developer: Sesisoft
Publisher: JCPlanet