Besides the tank.....what are the TOP 5 pieces of equipment you utilize for your reef tank?

[Roatan Reef]

In addition to what most said above...

Tube brush.
Different length Acrylic Rod to prode though stuff.
Mag scraper so you don't need to get prune hands all the time cleaning the glass.
Good gloves which goes up to the bicepts.
Feeder rings, so you food doesn't go into your overflow and waste it all.
RO/DI.

Now that you mention it, my Flipper 2n1 glass cleaner is amazing, definitely use that at least every other day. You can't beat it. , especially with the Razor blade side.