https://www.sudoku-today.com/en/ is a brand new sudoku website.
Sudoku-Today.com offers new Sudoku puzzles every day in 5 difficulty levels: Very Easy, Easy, Normal, Hard, and Very Hard
If you get stuck, there is two kinds of hint-buttons: Question mark and Random
Question Mark reveals the number in the marked empty field. Random reveals a number in an empty field chosen randomly.
If you like to solve your sudoku puzzles on paper, it is also possible to print each sudoku. It is formatted in a nice and user-friendly way.