T5HO gets you good lighting for the cost and is good for shallower tanks. Metal halides punch into the deeper tanks at the cost of heat and high electric usage. LEDs can get you the best all the way around, but tend to be pricey. If you do a search for "Doug's In Wall Build," he's got a line on some inexpensive (relatively speaking) Chinese built LED
panels that don't have all the fancy controls, but seem to work pretty well. LEDs are extremely energy efficient and the panels last a really long time. The high end ones are dimmable and you can program all kinds of neat effects and spectrums into them. Do not be duped into the Marineland Reef Capable units because the general consensus is that they are NOT reef capable.
I'm running a 6 bulb T5HO system on my 75 and a 150W metal halide supplemented by a 24" T5 blue on my 37.