Which plants have disappointed you the most?

Which plants have disappointed you the most?

I think every gardener has tried at least one plant (new or old) that greatly disappointed them. There are three plants I haven't cared for: Hydrangeas Pinkie Winkie, and Quick Fire haven't done diddly for me but hydrangea Limelight which I planted right next to them performed admirably last summer. Another plant I couldn't care less about, is Korean Viburnum "Aurora". The leaves are fuzzy and rather weedy looking and the small blooms are sweet smelling in a nondescript sort of way. I hate to say it, but they kind of remind me a little of babypowder for the two weeks out of the year they are present. So which plants have disappointed you?
I have a thing for red

I have a thing for red

Seedlings

Seedlings

back yard bats

back yard bats

Step inside my room.

Step inside my room.

Yard Waste Mushroom Experiment

Yard Waste Mushroom Experiment

Look at this DIRTY SMUT!

Look at this DIRTY SMUT!