Gloss paper will offer you a glossy finish, with an ultra-smooth, shiny surface and the photography will appear rich and vibrant in colour. Whereas if you opt for matte paper it will give you a duller, more subtle finish. Matte photos tend to be better for photographs which are monochrome or have a less vibrant colour scheme.
Would you like to put a particular photograph in a frame? In this case the best option is to have the photo printed in matte. This is because gloss print photographs cause reflections, whereas matte prints don't.