Personally I like to mix it up... in my 125g I have several bags of Eco complete, supernaturals black sand, supernaturals small golden gravel (like 5mm...or a little over sand size). I really like it because I have an overall black feel, but the gold/yellow really pops. Shoot, I think I also have some red flourite in there too.
125g semi planted. 2 silver angels, 14 silver tips, 16 white fin ornatus tetras, pair of Nicaraguense, pair of nototus severums, trio of firemouth cichlids. 2 FX5s, 1 1500gph circ pump, 2 48" LED lighs, and a HUGE piece of driftwood.
650g fish room. 15 30g tanks, 150g sump.