I agree that providers play a key role in the variety and innovation of bonus features. As I mentioned earlier NetEnt and Microgaming are really leading the way in this area. I would add that Play'n GO is also noteworthy, especially with their slots such as "Reactoonz" and "Book of Dead" that offer unique mechanics and bonus features. Personally, I think the key is to find slots that suit your preferences and playing style.

Great question, it's really interesting to discuss which game providers are the most creative in their bonus features. In my opinion, one of the leaders in this field is NetEnt. Their "Gonzo's Quest" slot with its innovative avalanche feature, where winning symbols disappear and new ones fall from above, creating extra chances to win, really stands out. Also worth mentioning is their slot 'Finn and the Swirly Spin', which uses spiral mechanics instead of traditional reels. Another provider that deserves a mention is Microgaming. Their game "Immortal Romance" is famous for its variety of bonus rounds, each of which is linked to a specific character and offers unique features. If you're looking for something really special, try slots from Yggdrasil. Their Vikings Go Berzerk and Valley of the Gods are known for their exciting bonus rounds and mechanics. I can't help but mention https://royalreelcasino.com/, where you can find a wide selection of games from these and other providers. This site is easy to navigate and offers generous bonuses for new players, making it a great place to find innovative slots.