toaster. Whatever I can do in the toaster oven but not in the toaster I do in a conventional oven. There's just not enough room in my little kitchen for a toaster, microwave, conventional oven AND a toaster oven.

Plus, I am addicted to toast, which is done perfectly and with very little wasted energy in my regular toaster.

toaster. toaster ovens are nice, but too small to do any good for me.

Counterpoint to zandar: you could replace the toaster with a slightly-bigger toaster oven, and for small jobs you can use the toaster oven and not have to fire up the big oven. It uses less energy, gets to the right temperature more quickly, and oftentimes lets you use the more appropriate heating technique due to it being "quick and easy" compared to using the big oven.

One of the clear advantages of a toaster are that it's designed for and excels in its purpose, e.g. the heating elements are not under the food. If you heat a lot of bread or other crumbly/messy food in a toaster oven, you need to be careful with crumbs or you'll have a nasty burning smell.

toaster/convection oven, hands down. if i could just haul my stove out to the curb (without a fight from dh) i would! i make just about everything in my little convection oven. toast, cookies, meat, shrinky dinks ;) LOVE it. xo