Pretty straightforward question, looking for something soothing with a crapload of puzzles like UnblockMe
Sudoku Touch!! Sudoku Touch, hands down. Uses hand writing recognition. Check it out.... http://itunes.apple.com/us/app/sudoku-touch+/id512397454?ls=1&mt=8
Have to agree -- Sudoku Joy is great for beginners and experts. It also includes some solving techniques that are very useful.
This has been asked a number of times in the past, and do looking at some forum searches will help you find a number of opinions. My favorite is Big Bad Sudoku Book for the best UI, and for unlimited puzzles. If you don't mind daily puzzles (having to wait for new puzzles everyday), 5 Daily Puzzles gives you 4 daily puzzles, of 5 different kinds - Sudoku, Str8ts, Kakuro, Jigsaw Sudoku, and Killer Sudoku. The advantage of these are they are all hand checked, as these are also produced for newspapers, magazines, and so the quality of the puzzles is difficult to match by apps that have algorithms for unlimited generation. Sudoku joy is popular, I found it OK. Jason Linhart makes it and a paid version which I have heard is better. Astroware also makes a very good Sudoku app. Much of your enjoyment is likely going to come from what features are most important. UI? Tutorials? Ability to import puzzles? Daily puzzles? Etc. if you can put some of those thoughts you will get some better answers, at least from me. There are hundreds of Sudoku apps, and so the features are what separate favorites at least for me. My favs are the ones mentioned above.
Yeah, practically all sudoku games are hideous. Pennypop's sudoku looks great though. it's free too which is always a plus.