Panner peanut butter is pretty good peanut butter and is quite crunchy, too. It's only NT$83, which is a good price.
I find that the Lysol brand of disinfectant works best when you need to mop your floors. Some of the Chinese brands are really strange and leave streaks and suds all over the place.
I recently saw Mott's apple juice for the first time at Carrefour.
And now you can move away from the ever-present Thousand Island dressing into new territory with Creamy Caesar dressing. (NT$129)
Also, in the cheese and yogurt section, there are several varieties of French "Dessert de Fruits" that are basically pureed fruits that are perfect for toddlers. Right now, you can get a pack of 4 for under NT$55. Some varieties are cheaper because they're expiring in the next few weeks. These actually taste really good and I've used them as substitutes for oil in recipes.
FINALLY! Someone is selling organic sesame butter (tahini?) for a good price! You can find this in the organic section for NT$149.
Also, the Armour TREET ham is on sale. (NT$79) There's a reduced fat version as well.