My largest pot was a bowl I threw about two weeks ago. I started off with 25lbs of clay, centered it and in the end I had a bowl with a diameter of 20.5in and a heigth of about 11in. When the bowl was ready leather-hard I ended up trimming 8.5lbs of clay from it, which made me realize I probably could have thrown something much larger.
As far as tall pots are concerned I regularly throw vases 14-15in tall, but haven't gotten past that point yet. ;) So who about you folks, what are the largest pots you've thrown?