Best Cracking Tool

There a few on the market. Some are paid some are free.
If you are new and have some money, I would suggest snipr. It has inbuilt configs which will make you understand cracking a bit more
once you have used snipr then move onto storm.it has a nice UI too but it needs configs which you need to find on forums, unlike snipr which has them inbuilt.
Then move on to Sentry MBA which is a little bit more complicated but you should be able to find a lot of tutorials on this since it has been around for a long time.