[f6bits]

Here's a nice long article with o-scope graphs:
http://www.screenlightandgrip.com/ht...enerators.html

Here's some random article with an output graph of residential power:
http://www.polkaudio.com/forums/show...-Plant-Premier

From what I've seen, a "proper" inverter generator has a very clean sine wave.

And here are some more traces:
http://www.doityourself.com/forum/el...ml#post1632416