The Life-Glo 2 or the Power-Glo would be the "brightest." I put that in quotes because it's not a matter of lumens, but of the spectra itself. Human eyes are most responsive to the spectra emitted by those lights, as they will reflect a little more off of the surfaces in the aquarium rather than be absorbed by the water.
Water absorbs the lower frequency wavelengths, (red, orange, yellow) whereas the mid level to high level frequencies (green, blue, indigo, violet) will be reflected because they penetrate the water. Everything you see is of course just a reflection of light, so the more reflection, the more you will see. Naturally that applies to your aquarium.
In a tank that's deeper, such as your 25h, that means you would do well to use a Power-Glo simply because it has a strong high frequency (Blue, Indigo) and a good mid. (Green) This will penetrate the water depth better than probably any others. Plus the yellow is especially strong on that bulb so it might just cut through the depth enough to give you a little more warmth and bring out some colors on your fish.
Keep in mind also that none of the Hagen Glo bulbs are "colored" per se; it's just that they emit different wavelengths at different intensities from bulb to bulb. Each one is made to suit different needs for whatever application you need. If you're not planning on keeping live plants, than I think you'd be pretty happy with the Power-Glo on its own. If not, just invest in a little more wattage by adding another fixture. This way you up the wattage and the light gets brighter. That's another way to penetrate the depths. Plus if you plan to do live plants you will need more than 1 watt per gallon, especially in a high tank.
Okay, science dork rant over. Enjoy your aquarium!
