Anyone looking for a medium to large aquarium for the first time might think they are all the same. Not so. There can be made of glass or acrylic, be tall or short, rectangular or bowed in the front. Here are my top choices.
1. Oceanic Systems
Oceanic makes the Cadillac of glass aquariums. Well constructed, they come in a variety of shapes and sizes ranging from fifteen gallons to over two hundred gallons. Matching canopies and stands are also available in several finishes. I've never had a bad experience with any Oceanic product.2. SeaClear Eclipse Compatible
Made from lightweight acrylic, SeaClear has created a product line that fits perfectly with the Eclipse systems. Guaranteed for life, the rounded corners will not chip or discolor as the seams on glass aquariums sometimes do. When combined with the Eclipse biowheel filtration and lighting system, it is one of the best. Just add a heater, and it's a complete package. 
3. Eheim
Known for their top of the line filtration units, Eheim also makes the cream of the crop in specialty aquariums. From Paludarium units to stunning show tanks, they package all the best components together. Pricey, but can't be beat for quality.4. SeaClear System II
SeaClear II systems combine lightweight acrylic with a wet/dry filtration system. For the fish keeper who has demanding needs, or who might be interested in changing to saltwater in the future, this is an excellent choice.