I discovered Sudoku when I first saw it several years ago in the Chicago Red-Eye, a free morning mini-paper published by the Chicago Tribune. It was a fascinating concept at first. Over the years, though, I have become a bit jaded, to the point where its main purpose for me is to pass the time on the train to work. For me, the puzzles have come to have a boring sameness to them. The Monday-Tuesday-Wednesday puzzles are too easy, the Thursday-Friday ones too tedious.
And yes, I recognize that true Sudoku fans consider all newspaper puzzles too easy, and go for the more difficult ones posted on these forums, or at least in the New York Times. I, however, have no interest in advanced solving techniques, with names like Flying Turtle Chicken Wings, Semi-Masked Non-Negotiable Triples, Jelly Fish Nets, etc. If a puzzle is hard enough to require such techniques, I lose interest in it long before I get that far.
I have moved on to Kakuro. It provides a much richer variety of solving techniques. I almost discover another new solving technique every time I work on another puzzle. Yet no one technique is all that difficult or tedious that it pushes me away. Decent Kakuro puzzles are available in major bookstores, right next to the Sudoku books. And, I have found three websites that feature Kakuro puzzles of just the right difficulty and interest. Those by Michael Mepham are the best.
Unfortunately, I have also discovered at least two websites with unacceptable Kakuro "puzzles" -- multiple solutions every time. The Internet is like a beautiful country meadow, loaded with mine fields that need to be avoided.
Unfortunately, Kakuro has not caught on well with the general public. Most daily newspapers don't have Kakuro at all. There are few, if any, Kakuro discussion forums. Even the Kakuro topic in this forum is largely inactive. It seems the entire world is like Chevy Chase imitating Gerald Ford in a presidential election debate: "Um, it was my understanding that there was to be no math .... "
I like new puzzle types -- but not those that require hours to solve or the invention of advanced new techniques. A new puzzle type should be interesting, not tedious. One example appeared on this discussion board a few years ago, something along the lines of: Each row, column, and box must contain two 2's, three 3's, four 4's, and nothing else. These kinds of ideas keep things fresh.
I have been thinking of a new puzzle type which sort of combines Sudoku with chess. If I ever come up with an actual puzzle, I'll probably call it Chess Sudoku if I post it here, or Sudoku Chess if I post it on the U.S. Chess forums.