I'm using Giesemann bulbs now; they are not much more expensive than other brands and seem to be the choice for nearly all of the serious aquarists I know (freshwater and saltwater). They came very highly recommended and I get a good price at my LFS. I've used combinations of both Coralife 6700K/Plant Flo and Current 6500K/Freshwater bulbs in the past. The Coralife bulbs were okay, but one started to hum after about 5-6 months and all bulbs seemed to loose intensity quickly. Without changing anything else on the tank I began to see an increase in algae growth and reduction in plant growth after about 4 months.
The Current bulbs were the stock bulbs that came in the Nova fixtures and are not worth mentioning.
The owner of my reefer LFS also likes URI and Hagen GLO bulbs, although I have no experience with either. He knows his stuff and runs a pretty spectacular pleco tank with Hagen GLOs. He offered them as an attractive alternative due to the different freshwater configurations (I think there are 4-5 freshwater/planted tank specific bulbs available?). I decided to spend the extra few dollars to get the Giesemann bulbs. I mean, what's another $18 when you're already dropping $200?
I'm currently using 4 x Midday 6000K bulbs and 4 x Aquaflora bulbs. The Aquaflora bulbs are very pink and give off a very warm light. The light from these alone seems unnatural and almost yellowish. I'm not completely happy with the light color, however the roommates, the girlfriend, and other non enthusiasts seem to like the warmth of the light.
The 6000K bulbs are a whiter, cooler light. The light is more natural and seems to bring out Iridescence in fish, especially the blue in the GBRs and the blue face worming in the Severums and Acara. The plants have no complaints.
I'm going to swap out two of the Aquaflora bulbs for some more 6000K bulbs in an effort to cool the tank down a bit.