There are three games I play a great deal: Guild Wars 2, Heroes of the Storm and a third that's currently in Alpha which I'm not permitted to discuss. All three are exceptional games and all are time consuming. I could passively play all three, not wishing to be great at either but as a competitive individual, it's not really in my nature to play an hour or two and have no objective.

Where Heroes of the Storm is concerned, I want to reach Rank 1. Despite the horrors of Hero League, it's easily possible but will take a significant amount of time and effort to play the games needed. Doing so means I'll be unable to invest the time neccesary to keep up with Guild Wars 2's PvP scene as well as its living story.

Finally, the third game I'm playing is only available a few days a week at the moment and is gaurenteed to eat up all my time when the servers go online. Juggling these three games is proving incredibly difficult and I'm not sure it's possible in the long term (it's a headache enough in the short term). 

Now I've had my say - what about you? Do you play more than one MMO at a time? How do you juggle them? Do you only play one game at once? Let me know.