Used Car Financing

What are the best financing options for buying a used car?
I’m interested in buying a used car and my credit is pretty good. I’m considering the following options:
• credit union
• bank
• online lender
Among those choices which one do you recommend? And are there any particular companies that are worth considering?
Credit union i always going to give you a better intrest rat than the other choices. Bank would be your second best option.