I use https://lastpass.com - LastPass - it is free and very easy to use! :-)
I use - https://www.roboform.com/ - very nice and small tool not only for creating passwords, but you can use it for submitting your site to various directories - semi-automatically. :-) Very useful for local sites and boosting their rankings. Anyways - you can also use it for password generating purposes! The price is low as well - $9.95 for a whole year (the first one) and $19.95 for the next year(s)! hope that helps!
Here is another tool - no install, no setup - very, very easy - https://onlinepasswordgenerator.com/