A national sales tax...
...is the direction I would love to see things head, but it will never happen in my lifetime. Naturally some things would need to be exempted (food, medicine) and that immediately causes problems. It would hopefully encourage saving and people wouldn't be punished for making profitable investments (as interest, dividends and capital gains would not be taxed), nor would they be supported by having a write-off for foolish ones (if the stock you bought plummets in value, bummer - no write-off - maybe you should have selected more carefully). The sales tax rate needed may be astronomical, but it would make people more carefully consider their purchases (maybe I go for the Ford because including tax it's a LOT cheaper than the Ferrari).
The need to prepare sales tax returns would obviously be much greater, but the average Joe wouldn't really have any recordkeeping requirements. April 15th (or October 15th for those on extension) would be a day just like any other.
Jim