The type of light that is best for aquariums depends on the type of aquarium you have and the needs of the aquatic life within it. Here are some common types of lights used in aquariums:

1. Standard Aquarium Lighting: For most aquariums with freshwater fish and live plants, standard fluorescent or LED aquarium lights are sufficient. They come in a variety of sizes and are energy-efficient.

2. Full-Spectrum Lighting: If you have a planted aquarium with live aquatic plants, you might want full-spectrum lighting. These lights provide a range of wavelengths that promote healthy plant growth.

3. Actinic Lighting: For marine or reef aquariums, actinic lighting is essential. It mimics the blue and violet wavelengths found in deep ocean waters, promoting the growth of corals and enhancing the coloration of fish.

4. LED Lighting: LED lights have become increasingly popular for their energy efficiency and versatility. They are available in various spectrums and can be customized to suit different types of aquariums, including freshwater, planted, and marine setups.

5. Metal Halide Lighting: This type of lighting is very bright and often used in large, deep aquariums or in reef tanks with light-demanding corals. They can generate a lot of heat and may require additional cooling.

The choice of lighting also depends on the specific needs of your aquarium inhabitants. It's important to research the light requirements of your fish and plants and select lighting accordingly. Additionally, consider the aesthetics you want for your aquarium, as different types of lighting can affect the overall appearance.