Paper towels because it's easy to just grab a roll. Also a big package of paper napkins. I don't use the upper shelf because I'd need a step stool.

I didn't like the hinged door on the L shaped cabinet, so I'm happy with my choice.

@mayflowers - thanks for the response.

Didn't think of paper towels and saw myself constantly taking out the items in the front to get to a bowl or something in the back...

Things I don't use very often like large Tupperware cake holders. Yes, I still have some. LOL I don't have a blind corner in current kitchen. I eliminated it.

I'd planned to have a void in the corner so access wouldn't be an issue, but wound up with 12" of blind space anyway (long story), so I put less-used stuff there also -- quiche pans, pie plates, etc. It's still pretty prime real estate there, so I don't store the almost-never-used stuff there.

In the last kitchen that I had a blind corner upper, that's where the giveaway vases went. I tend to buy them at thrift stores and garage sales, and when I have an event that dictates that I cut flowers for it, I grabbed one out of there to give to the recipient and no one ever needed to worry about returning it to me. My laundry room cabinet serves that purpose now that the blind corner is gone.

Things I rarely use, like specialty servings pieces, etc.

Also overflow dishes that are used as backups.

Glasses and coffee cups- don't need the ones in the back until you've used the ones in the front so you can get at them.

Blind walls are often a net gain in storage even discounting the corner so just consider it a bonus.