These are some of my personal favorite alphas that i use in my projects. Feel free to get creative with them by layering different alphas on top of each other. These alphas would be classified as industrial so it can come in handy for any quick hard surface detailing.
To fix jagged edges that are sometimes visible by applying the alphas, smoothing it a little bit by sacrificing some of sharpness applied by the alpha should fix the problem. Alternatively you could sub-divide your model further.
You can also use an alpha to create quick geometry using Shadowbox.
For optimal results, make sure your poly count is fairly high in order to get crisp details.
Enjoy them and have fun creating!