Broccoli (in large amounts)
Chocolate (the darker it is, the more dangerous it is)
Coffee grounds, beans & tea (caffeine)
Garlic (in large quantities)
Hops (used in home brewing)
Pear pips, the kernels of plums, peaches and apricots, apple core pips (contain cyanogenic glycosides resulting in cyanide posioning)
Potato peelings and green looking potatoes
Products sweetened with xylitol
Raisins and grapes
Tomato leaves & stems (green parts)
some of those aren't that common to me (hops, rhubarb leaves) but they may be common to someone else so i think its important to list it.
i know joey made a PSA about grapes and macadamia nuts a while back. perhaps he or bentley or another dog that is crafty in photoshop can make a cute graphic with the finished list so we can post it in the info (instead of in the memories where it might be forgotten)?