which os is best for Dolphin?

[Nikitastepanov]

which os is best for dolphin?

[JosJuice]

If you want to use USB microphones or emulate the broadband adapter, use Linux. Otherwise, I guess both Windows and Linux work well. But I haven't really used Dolphin much in Linux, so maybe others have something else to say.

Also, if you're using Windows, you should be using Windows 8 or newer.

[Helios]

Regardless of which OS you use, a lot of games aren't going to emulate at full speed on your hardware.

Your selection of OS won't make that big of a difference.