THE AQUASCAPER'S CHOICE
For now, the ADA 120p ( 120 x 45 x 45 cm) commands what is widely considered the golden ratio in height + depth + length. It has enough volume for serious aquascaping, yet it is not as cavernous to fill with hardscape compared to slightly larger dimensions that push costs to escalate sharply. Many competition scapers in the IAPLC use this dimension.
My current (mid 2017) ADA 120p
"modified 120p with more depth"
Same length & height as above, but with more depth (120cm X 60 x 45). This complex scape by Roger Goh uses a deeper tank to give more room for creating structures & increased depth perception.