If your doing just the basics then you can get away with T8's, cheaper initial setup cost, but more expensive long term, T5HOs are a good medium and work extremely well, yet again they have a higher long term cost (replacing bulbs, power useage etc...) LED's are a good choice if you want to spend now save later, make sure you get a good brand though as some cheapies burn out quickly making them a waste of $$$ (just ask Sheepsnana) Metal Halides are good, but expensive both in setup and longterm costs , imo they are a bit out dated now
You want to aim to get bulbs high in the red and blue spectrums to promote plant growth and in the green spectrum to make your plants look bright, I use 1-2 x Tropical bulbs (high red and blue) and 1 x sunlight (a little more green) in my lowtech tanks and get good results