I bought one of the textured silicone backgrounds for my 45-bowfront freshwater tank and built a custom cabinet stand shaped like the tank . It remains one of the most beautiful tanks I've ever done. Never could keep it well-planted because Dwane (plecostamus in my avatar) constantly re-arranges things. My youngest daughter has the setup now.
I went saltwater because I always wanted tangs, puffers, anemones, starfish, big crabs and an eel. Corals are beautiful but it's truly the diversity and color of saltwater that drives me. Dwane has a boatload of personality, but he's about the only freshwater fish that comes anywhere close to saltwater species.