I think that Netflix was probably the first one I downloaded. Just had to see the new screen in action. Wordament, Kindle, Box, All Recipes were pretty early on as well.
I haven't tried, but I would think that youtube would work fine in the browser if you wanted to use it, but maybe I'll install MetroTube and compare.
Is there no official LinkedIn app? Again, I am sure this works quite well in the browser. I'll have to check that out.
So far, I am happy with Internet Explore, but why is there no home button on the metro app, but there is on the desktop version of it. Maybe I am one of the last home button users out there.