Better Isn't Necessarily Bigger
First, it depends on what you mean by "better."
I can give you a rational argument that sRGB is better than AdobeRGB, despite sRGB being a "smaller" gamut:
sRGB is better than AdobeRGB for 8 bit images as sRGB's smaller gamut makes better use of the lower bit depth and reduced Delta E errors.
If you mean "bigger" keep in mind that if you use a larger gamut colorspace than sRGB, you ALSO need to use a higher bit depth to have reasonable and minimum distance interpolation between values.
That said, DCI P3 is the colorspace used in theaters. And that system uses 12 bits with a gamma of 1/2.6
If you have a home cinema, then you might think you want a P3 projector or monitor — though what are you going to play through it? There are maybe a handful of Blurays mastered in that larger colorspace. Regular HD is still Rec709 (same color primaries as sRGB).
There is progress being made with HDR monitors, such as for Rec2020.
What is your specific application? What are you doing? If your work is not using bright highly saturated colors, then sRGB is very likely ideal. You only need a larger space when your image "won't fit", i.e. colors are being clipped.