I think your question is too vague. Can you specify the tank size, location (built-in, tall, low etc), FW or SW, planted (lots of candle power?), big fish or small (big fish need big openings), material (stainless, wood, glass etc), access requirements (twice daily feedings or automatic feeders?). Is heat a concern? How important is appearances?
On one built-in tank I fixed twin flourescents to the wall, and another two to the canopy. It has 3 access stages. First stage is for weekly access (small hinged front, small glass section to open, autofeeders the rest of the week). The 2nd stage for heavier maintenance has the canopy and front bulbs angle upwards 45 degrees. The 3rd stage, the canopy slides off and leaves a shell frame holding the back lights in place.
The tank I'm working on now will probably have a 5' stainless steel custom canopy, lined with programmable banks of Luxeon LEDs to simulate dusk, daylight and spot/accent lighting (if I can afford them ;~). Lots of light-power means lots of heat and the canopy must be designed with ventilation requirements in mind.
Another tank had a wooden box built, with a small compartment on one end

which hinged open for daily feeding. This was a heavy canopy, so feeding access just made more sense from the end and maintenance from the back (from another room).
Sometimes the canopy is just part of the stand, which comes up the tank sides to cabinets above. Glass tank covers and a piano-hinged wood panel which locks open at the front is all you need (lights are installed to the underside of the cabinets above).
Just a few ideas to ponder as applicable
cheers