Blizzard has been on fire lately.
I'd never played a MOBA style game before, but over the past year I've played 360 matches in Heroes (a full circle!). Matches typically last about 20 minutes, which means that I've put something like 120 hours hours into this game. I think it's safe to say that I'm addicted.
Heroes of the Storm is free to play, has a great tutorial so you don't feel lost, games are quick and exciting, it runs on both Mac and PC, and it's available to everybody and their mother starting yesterday. Do yourself a favor and check it out.