I've looked into these a lot previously. The one thing I found - if you go tropical with these aquarium coffee tables..... you'll get condensation on the top. As we do on the condensation trays / sliders on our aquariums.. Therefore, defeating the object if viewing fish from above with these tables.
My vote, some nice fantail goldfish / fancy goldfish. They look amazing from above. Black sand / black bare bottom, no heater required, personable fish, win (in my opinion).
View attachment 1400597
View attachment 1400598