sRGB is a small gamut colorspace. Stardardize on it only if you will be using your images for web and computer display.
If you will be printing your images, Adobe RGB is a wider gamut space that is better for printing workflow. You can always convert images to sRGB when you downsample them for web use , leaving the original file in wide gamut with the full color range. Once an image is converted to sRGB, the lost color gamut can't be recovered.
The link below has a chart showing device gamut vs. colorspace gamut. The center two images show the fit difference between Adobe RGB and sRGB: