I can't think of anything I've out right banned from any of my Sims lots. However, there are objects that I don't use very often just because, as others have mentioned, they're so large; microscope, telescope, cupcake machine, etc. I do get rid of sinks as soon as my Sims can afford the dishwasher though. Usually not because of their water drinking obsession, unless it's a house with uncontrollable Sims. I get rid of them because of the obsessive hand washing after using the toilet.
Yes, I know it's expected in the real world, and I'd be grossed out if nobody did, but this is the Sims. What sense does it make to wash your hands if you're getting in the shower next? Especially when the only sink is in the kitchen located on the other side of the house to wash dishes. It's just an annoying time waster in my opinion. *shrugs*
