Now, I know that some of these items are probably already suggested, but a long nice list is a nice thing to have at times. Me and my roomies sat down to consider some stuff we'd like to buy from the store (we seem to spend insane amounts of money on the CS store, and are getting a little bored of the items currently available), for seriously, we love the store and decorating our pups!
Ready for a marathon list?

As a dog fan, I'm suggesting these items for dogs, obviously.
Cop set - Hat, jacket, 'gloves', belt+pistol, 'baton'.
Brighter/darker angel wings - a lot of the current wings are so pastel that they don't fit the darker/brighter dogs :/
Demonic wings - in different colors like the angel wings.
Grey/black/brown/beige angel wings - some like the earthy tones as well, and CS has a lot of brown and grey dogs :3
Horns - all kinds and colors! Bull horns, curly ram horns, small horn, spikes, antlers etc.
Weapon set (buying the ninja set over and over again for the katana is not fun) - Katana, Broadsword, Viking axe, Spear, Scythe, Dagger.
Indian/native american set - facepaint, headdresses, bead necklaces, feathers, dress/pants.
Uniform - long jacket, army hat, pants, shiny shoes/boots.
Unicorn set - we have dragons and phoenixes too!
Jewellery/piercings - earrings, studs, cross necklaces, bracelets.
Music set - headphones, radio, mp3 player.
Collars - in many colors and without the spikes.
Socks for hind legs - we've got some for front legs, how about giving the cute backside some attention too?
Glasses, sunglasses and visors - in many colors like blue, red, green and black.
More toys - bright rubberballs, chewtoys, rubber chicken.
Sailor set - hat, shirt, pants, shoes...anchor? XD
Hats - cowboy hat, fedoras, top hat, sombrero, baseball cap.
Bandanas - in all colors of the rainbow, and more!
Food - bananas, lemons, bottles, chicken, ham, cans, pasta hanging out of mouth.
Scar set 2 - with scars that go over the eye, over the mouth and such.
Ninja scarf set - in different colors than just black.
Artist set - palette, paintbrushes, paint splotches, pencils, sketchbook.
Gun set (hey, we have katanas and those things are lethal weapons too)- Bazooka, Rifle, Pistol, Uzi.
Cyborg parts (to go with the guns, as an example, but not in the same set please) - Cyborg eye, ear, leg.
Masks - eyemask, half face mask, whole mask.
Bows - for tail, ears and neck.
Manes - some like manes better than wigs.
Fairy sets - colorful butterfly wings.
Armor - eastern and western respecitvely. Helmets, chest armor, etc.
Rave set - goggles, light sticks/bracelets, glowy lenses.
Hippie set - wig, colorful clothes.
Neckerchiefs - more colors~
Bracelets - also more colors~
Socks - more patterns, whole color, socks with small bows etc.
Whew, that was it, I think.
This list brought to you by:
DiabolicReality, AngelicPain and MonniTsuki.