Jacob N. Breetvelt

This plugin can display a sudoku puzzle diagram on your website. 
It comes with 200.000 unique puzzles in 7 different levels of difficulty. 
The number of times a puzzle is successfully solved or failed is registered. 
There is simple help and statistics available at the front-end.

WP Sudoku Plus

This plugin displays a sudoku puzzle diagram on your website that the visitor can try to solve.

wordwebsoftware

Simple upload of interactive puzzles exported by Crossword Compiler, or conversion of puzzles already posted to the 
https://crossword.info website.

Crossword Compiler Puzzles

Insert a crossword puzzle, sudoku or word search from content made by Crossword Compiler

WP Sudoku Plus vs Crossword Compiler Puzzles