Free iPhone Game Of The Moment: Enjoy Sudoku Daily
There are a lot of Sudoku apps out there, but this is easily the best one I've found in months of searching. You'd think that it wouldn't be that hard to not screw up something as simple as Sudoku, but this is the only one that doesn't have a terrible interface, annoying graphics, or some other failure.
Enjoy Sudoku gently takes you through a series of tutorials if you're new to the game. Afterwards, you can take on 10 difficulty levels of Sudoku each once per day (in the free version; $3 unlocks unlimited puzzles).
I thought I'd quickly break down and buy the paid version, but in practice I find that I enjoy taking on a few different difficulties of puzzle in the event that I want to do more than one Sudoku a day. Next time I get stuck at the license bureau or in line for a midnight launch I might break, but I haven't been tempted at all in the few weeks I've been using the app.
The reason this version of Sudoku is superior to everything is all interface. It's a little ugly, as you can see from the screenshots, but it allows a great deal of customization over how you input numbers and notes. Personally, I find that setting the input method to "number, then grid" rather than the default hybrid style works the best, but the options are there.
As I've said before, I can't have enough puzzle action on my phone. Especially the free kind. Hopefully this helps out anyone out there with an iPhone, iPod, or iPad.