Not in a tank. Goldfish get very big and messy. I have one out in the pond with the 7 koi. I don't want anymore out there because they will just keep breeding and make hundreds of babies.
I've had multiple fish tanks over the years. Nothing huge. Had a 20 gallon with some goldfish, and currently have a 5 gallon with some guppies. For some reason the guppies keep randomly disappearing so im down to only 2. We also have a koi pond outside.