I've been to Nautilus... I'm not much into the types of fish they have, but it's a fun store to browse.
Aqua Serene has three parts... the front part of the building is hydroponics. The center is aquarium stuff, and outside is pond and garden stuff. The tanks are all sparkling and the fish are active. One of my favorite parts is the large koi pond you see when you enter the aquarium portion of the store. Next is the saltwater fish and supplies, then freshwater fish and supplies, and finally plants. Almost all the freshwater tanks are planted and the plants are thriving. They carry a wide variety of fish and invertebrates, though they seem to be out of the small shrimp at the moment. My husband fell in love with the stingrays. Yes, they had a freshwater tank of small stingrays. Their plants look very nice and are grown in separate tanks without fish. While some of their pricing can seem a bit high, I figure if the livestock is healthy and active, that's a bonus right there.
They have a large area with hardscapes, too. Big bins of various pieces of rock and bogwood are reasonably priced by the pound. They also have several items that can be used for scaping saltwater tanks. I didn't see much in the way of nano tanks (my personal favorite), but they do sell giant and moderate sized tanks. They have several ready-to-take-home betta set ups, though they're a bit small for my taste. Most of their freshwater substrates consist of regular aquarium gravel or various sands. FloraMax was the only nutritive substrate that I saw in stock. They do seem willing to do special orders on request. When my 4 gallon is cycled, I'm going to use them to order my boraras urophthalmoides since they don't seem to be common around here.
I like the idea of getting my neocardinas there, but I'll probably stick to TPT shrimpers for that.