I have my toaster oven there set on an angle across the corner. It's a nice new stainless steel one, looks good and is convenient to use.

Same here, the corner is big enough to fit the toaster oven and you don't lose more "usable" counter space.

We have a flat screen TV:

I have two corners, and will have two corners. Sigh. The one with an upper cupboard (only on one wall) has the paper towel holder (came with house), and coffee makers and teas (only used for company). The other corner (no upper) has the boards and racks for which there is presently no cupboard, the waffler when it's not stashed away, the crock pot when it's not stashed away, etc.

In other words the corners are junk accumulators :)

Sorry. Lost the suggestion part of the above :)

Whether it's a toaster oven, TV or crockpot, corners are great places for appliances that don't need much tending.

You mentioned decor, and if you like decor (vase of flowers, ceramic chicken, etc.) on your counter the corner is an excellent place for it, because, again, decor doesn't take tending.

I'm considering putting a prep sink in one corner because that's the only way one will fit, but I hate corner sinks :)

Thank goodness I'm getting rid of that corner -putting my Advantium cabinet on the diag. there. But we had our wine rack pushed back on the diagonal under the upper cab. Perfect place for it!

how about a small corner shelf? or cookbooks and bookends? or one of those big utensil holder thingies?

I have two small shelves at right angles in the corner. There are dessert dishes and saucers standing up with extra large mugs in front. Under the one shelf are my canisters given to me by my grandmother.
{{!gwi}}

We have a Bose wave radio/cd player there. It's a convenient place for it and isn't bulky enough to make the corner feel too crowded.

We will have 2 corners...

One will be on the peninsula and we will have our prep sink there...easy access to the sink from DR or kitchen. I think having the sink in a corner on a peninsula is less intrusive to seaters than having it on a leg of the peninsula.

The other corner will also be a mini-peninsula but no seats. This corner will be my baking center so I plan to store my KA mixer in the corner. Using a corner as a baking center gives me more room for all those ingredients and tools used during baking and keeps everything more easily within reach than a straight counter with the same amount of workspace...especially when cookie baking!