If you want a standard sized tank (< 240 gallons), buy a glass tank. It's cost effective and at that size, you don't quite need 10 people to move the thing.
For large, custom tanks, acrylic is the only way to fly. Thick panels of float glass have a noticeably green tint. They also weigh a ton (literally), cost a lot, and can break if not built perfectly. Acrylic scratches easily, but glass is just too much to deal with when you get into really big tanks.