If you want something close (within an hour) - The Dive Stop in New Melle
If you are willing to drive (4-5 hours) - 1st pick Mermet Springs, 2nd pick Haigh.
Mermet: Great people, Great owners, and lots to see. 727, bus, ambulance, firetruck, many platforms. Great diving for shollow or deep divers. Very professional, great accomodations, covered pavillions, hot showers. I make a trip 5-6 times a year and I'm 6 hours away.
Haigh: Typically very god viz especially if you can get there during the week. Not as many attractions as Mermet, but a fully dedicated dive quarry with a great owner as well.
Snagel