In my opinion, India comes first, followed by Pakistan, Sri Lanka and then maybe Bangladesh.
India can produce all types of spinners with ease. And see their backup and emerging spinners are good enough to play for most other teams. India are just not patient enough with them. For instance Amit Mishra is a terrific leggie, yet he is just not good enough for them.
Pakistan always produces quality spinners. They might not have the numbers of India, but individual capabilitywise they always have terrific players. Mushtaq Ahmed was replaced by Saqlain who was replaced by Kaneria, and now Ajmal. Pretty soon they ll have someone else.
Sri Lanka also has a lot of good spinners. But heres the problem. Everyone expects a Muralitharan. But you cant always produce Murali's.
Surprised to see 41% believe Bangladesh produces the best group of spinners. True we have a lot of spinners, and competition is intense, but individual quality wise they are not world class. Shakib for instance solely relies on accuracy, arm ball, and the orthodox spin deliveries, same could be said about Razzak. In comparison Herath has the carrom ball, the one that goes the other way, and a number of other mystery deliveries. So while you will see Herath destroying batting lineups, Shakib perhaps wont do the same. This is why having someone like Saqlain is important on full time basis. Pakistani youngsters have people to look upto, learn from. Same with Indian kids and Sri Lankans. In Bangladesh apart from Rafique there really isnt anyone to inspire the next generation.