Note: Neither I nor this site is responsible for anything dangerous you do with these chemicals. Also, these are just the chemicals that I know off and can personally confirm buying/seeing in stores. Everything here is from first hand experience. That being said, you may be able to find more or less chemicals than me depending on how hard you look and where in the U.S. you live.
Acetic acid- vinegar
Acetone- certain nail polish removes; hardware stores as all-purpose solvent
Aluminum- aluminum foil, pipes, soda cans, etc.
Powdered aluminum can be found inside an etch-a-sketch and in some metallic paints.
Aluminum sulfate- sold in gardening stores
Ammonium nitrate- in certain "instant" cold packs
Ammonium phosphate- sold in gardening stores as a fertilizer
Ammonium sulfate- sold in gardening stores as a fertilizer
Argon- industrial gas supply shop
Aqueous ammonia- household ammonia in grocery stores; industrial janitorial versions are more concentrated
Bismuth- use in lead free hunting shot or fishing weights
Benzoyl peroxide- in acne creams
Boric acid- solid sold as insect repellant in hardware stores; very dilute solutions sold as eye wash
Butane- camping fuel
Cadmium- inside Ni-Cd batteries
Calcium Carbonate- chalk, eggshels
Calcium Chloride- sold for use in pools and humidifiers
Calcium Hydroxide- sold as slaked lime in gardening stores
Calcium Hypochlorite- sold for use in pools
Calcium Sulfate- plaster of paris; gypsum for gardening
Carbon- BBQ briquettes, graphite rods in batteries, pencil lead, activated charcoal at aquarium stores, charcoal for drawing at art stores
Carbon Dioxide- dry ice at grocery stores
Copper- wire, pipes
Copper sulfate- sold in some hardware stores as a root killer
Cyclohexanone- in PVC primer
1,4-Dichlorobenzene- in some mothballs
Ethanol- wine, vodka, denatured ethanol
Ethyl acetate- some nail polish removers
Ethylene glycol- most anti-freezes
Gold- jewlery
Glycerine- pharmacies
Hydrochloric acid- sold as muriatic acid at hardware stores
Hydrogen peroxide- 3% solutions for medicinal purposes
Iodine- tincture of iodine for medicinal purposes
Iron- anything steel
Iron(III) chloride- solutions of it are sold in electronic stores as PCB etchant
Iron(II) sulfate- sold as a fertilizer in gardening stores
Lead- lead solder; lead shot for hunting; lead weights for fishing
Lithium- lithium batteries
Magnesium- firestarters at camping stores
Magnesium citrate- solutions of it are in some grocery stores
Magnesium hydroxide- milk of magnesia at grocery stores
Magnesium sulfate- Epsom salts at grocery stores
Manganese(IV) oxide- alkaline batteries
Mercury- thermometers, barometers, etc.
Methane- natural gas
Methanol- some anti-freezes
Methyl ethyl ketone- sold in hardware stores as a general solvent
Naphthalene- in some mothballs
Neodymium- neodymium-iron-boron magnets found in hard drives
Nickel- some coins; Ni-Cd batteries
Nitrocellulose- ping-pong balls
Nitrogen- liquid nitrogen at industrial air supply shops
Nitrous oxide- whipped cream containers
Oxalic acid- sold as wood bleach for decks in hardware stores; in some stain removers
Oxygen- industrial air supply shops
Platinum- jewlery; some esoteric old razor heads; in a powdered form pasted on a ceramic substrate in catalytic converters in automobiles
Potassium chloride- sold as salt subtitute at grocery stores
Potassium nitrate- sold as stump remover at some gardening stores
Propane- fuel sold in grocery and camping stores
Propan-2-ol- sold as isopropyl alcohol or rubbing alcohol in grocery stores
Propylene glycol- some anti-freezes
Silicon dioxide- sand, quartz
Silver- some old coins, silver solder, jewlery
Sodium borate- borax in grocery stores
Sodium bicarbonate- baking soda
Sodium bisulfate- sold as pool chemical
Sodium carbonate- sold as a pool chemical
Sodium chloride- table salt
Sodim hydroxide- sold in some drain cleaners
Sodium hypochlorite- bleach
Sodium percarbonate- OxyClean in grocery stores
Sodium phosphate- sold as TSP in most hardware stores
Strontium nitrate- in red road flares
Sucrose- table sugar
Sulfamic acid- used in some toliet bowl cleaners
Sulfur- sold as powder at gardening stores to prevent insects from eating plants
Sulfuric acid- some drain cleaners (concentrated), battery acid (dilute), some pool chemicals (even more dilute)
Tin- lead solder
Toluene- in some hardware stores as a solvent; also sold in some hobby shops for removing glue
Tungsten- light bulb filaments
Water- duh
Xylenes- in hardware stores as a solvent
Zinc- inside of pennies; alkaline batteries