As an American, I also have to go with my own.

If I had to choose any other, I think Italy has a nice bold one.

NarniaLover, yes, I think it's safe to say a huge portion of NarniaWebbers are American. But there are members from all over the world, including Australasia, Europe and Africa.
I really love that rendition of the Finnish National Anthem and the (VocalNationalAnthems YouTube channel) Brazilian Anthem is also very good. Others just seem a bit boring or in bad taste (musically I mean). I also enjoyed the 2000 Sydney Olympics ceremony rendition of 'Advance Australia Fair'. It's probably the best version I've seen.

I only know the american and australian and british ones well so i can't say.

...I like it too, except it is a bit long...

I've noticed that the performances I've found online always seem to include all three verses. Is that typical? (for comparison, "The Star-Spangled Banner" has several verses as well, but usually only the first is performed).

Yes it is typical to sing the whole anthem, at least I've never heard just one verse being sung And since the chorus is repeated three times so it turns out to be pretty long.

I'm ~60% Filipino, so I like that one of course. I actually had to sing it with two other friends in front of a ton of people at a party recently...
Otherwise, I'm biased towards Star Spangled Banner.