I own both a wii and a copy of mario galaxy... 

Would it be acceptble (both legally and morally) to emulate the game on my PC?

Straight up piracy is wrong, of course, but I mean, it's not like I refused to pay nintendo for any of their work...

I am sure it's illegal to rip/download a copy but I am sure in court, since you own a copy, your case might hold ground since it shouldn't count as a lost sale or anything. Alternatively, you could always get a DVD reader which can read your wii games.

Morally is up to you...

For me, if I own the copy, my morals are a okay and I don't care much about the legality nonsense. Then again, even if I don't own it, my morals dont care.

For me, it is. I still play a lot of SNES games on my PC. And I think most of people do the same

Emulation is better than acceptable. It's great. Emulate everything.

the the company doesnt lose money from it, then there is no harm in doing it

That's awesome, actually. Commendable effort.

Personally I never do it. I support the games new if I can. Older games still play it on the hardware. Other than that I still purchase them legit on a service.

Yes.

I prefer not t as i like playing them on the hardware itself. However no objection to f you rather play on PC.