^In slots, the game can be classified into several groups based on its volatility. The higher the volatility, the higher the win multiplier. It's a bit like the risk and return relationship. Winning is more often in low volatility slots, but the winning multiplier will be lower, and vice versa.
Top-20 monthly slots ranking (June):Book of Dead - Play'n Go
Starburst - Netent
Bonanza - Big Time Gaming
Wolf Gold - Pragmatic Play
Reactoonz - Play'n Go
Piggy Riches Megaways - Red Tiger
Eye of Horus Megaways - Blueprint
Eye of Horus - Blueprint
Gonzos Quest - Netent
Rich Wilde and the Shield of Athena - Play'n Go
Buffalo Blitz - Playtech
Fishin Frenzy Jackpot King - Blueprint
John Hunter and the Tomb of the Scarab Queen - Pragmatic Play
Mustang Gold - Pragmatic Play
Reel King Mega - Red Tiger
Mega Moolah - MicroGaming
Dynamite Riches - Red Tiger
Trollpot 5000 - Netent
Cleopatra - IGT
Age Of The Gods: God of Storms - Playtech
Source:
http://www.igamingtracker.com/egr-top-20-rankings/Starburst and Book of Dead remain strong in 2020. I wonder which game will topple these champions. Honestly, these slots are kind of outdated if we judge it by the gameplay.
Perhaps Book of Dead lovers should try Legacy of Dead. It's similar but newer (released in Q4 2019).