No, I'm afraid not.
There are illegal ways but they require hardware modifications, and they also come with implications!
Are you on about Virtual Concole games? If so, you still can't get them for free, but on the pc you can download plenty of emulators for free aswell as games for them, just google it, i use to play on a mega frive emulator, and picked up 2 usb control pads for pretty cheap, and i was sorted.
If you wanna download full Wii games free, just PM me!