Welcome to Gaia! ::

I vote for 5, 6, and 9.

Im a photographer also, and I think the angles are beautiful in those!

The photos that I can really picture being used in someone's home/office would be 1, 5, and 9. Mostly because they seem to not be so obvious at what it is we're looking at, and the colors (or lack of) seem to be the sort that people would most likely choose to have framed.

I really do like number 8 for its crispness and lovely contrast in depth and colors, but for some reason... it strikes me as something more appropriate for sale as stock photos. The same goes for #7.

I dunno much about the whole printing stuffs, but I did have to print out a photograph of my gf's dad who passed away. I had to do extreme modification to one of his photographs, and it looked great when printed on some glossy photograph printing paper we had for a while. Sorry I can't be of any more help. ^^;