If a system leaves your ears ringing its not a good system, or the sound engineer hasnt got the levels right. A good system should be loud but clear and leave you able to have a conversation still without shouting.
Whenever i've heard the system in the Box at Ministry it has sounded very very good. The only ones that have come close in the UK were Home when it was open, Fabric, Code when they get the levels right which is not often these days and they have fcuked/damaged speakers and mixers/sound processors by not having the levels right (too high, DJs need to learn that when all the red lights are flashng its too high!) on many occasions.
One of the best systems i've ever heard in a smaller club was in a place called Player in Northampton. Everyone who has heard it and knows what they are on about (a lot of top DJs included) has commented on how good it was. Unfortunately it has closed down now.
The thing with a very good system is that it has got to be designed for a specific club, a la Home,Twillo, MOS,Fabric. Obviously this costs a lot so many clubs go for a generic system from people like JBL,Peavey,L accoustic audio etc. This will sound ok but not as good as a custom system.
The system needs to be adjusted throughout the night as well, when the room is full it needs to be setup very differently from when it is half empty or you end up with sound bouncing off walls etc.
The system in Eden is meant to be one of the best in Spain, so they say but i've never heard it set up well. The system that Space brought in to the main room last year for Sundays and Carl Cox was pretty damn good considering it wasnt designed for the cluband was basically a 'mobile disco'.