As everyone else says OP it's very much a case of trial and error and your own personal taste. Gluten free bread is a particularly divisive topic, mainly because most of it is SO bad!
My current favourite is BFree Brown Seeded Loaf, but it's £3 for a small loaf, so it's far from cheap. Sainsbury's used to do a really nice seeded loaf in their Free From range, but they changed the recipe last year and it's horrible now - really dry. Some GF bread is very bloating, thanks its blend of different flours and things like potato and tapioca which bulk it out, so all you can do is try them all. M&S sliced GF bread makes me blow up like a balloon.
The corn pastas are high GI, so I find they spike my blood sugar up and make me very agitated after about an hour. Dove's brown rice one is good, although it does stick together in a lump if you don't stir it.
M&S Made Without range has very nice fresh quiches, as does Sainsbury's Free From.
Jus-Rol does good GF pastry, but I can only ever find puff, not shortcrust. I think Schar do a shortcrust pastry, but I can't ever find it - I think you can get it through Ocado maybe?
You can get good range of gluten free pizzas in Waitrose.
As for treats, really depends what your DH likes. I love Prewett's Dark Chocolate Ginger cookies - they're so nice you wouldn't know they're GF - available from Waitrose. The Sainsbury's Taste The Difference ones are pretty good too and they do nice Triple Chocolate Cookies.