1.”Howdy Partner.” Unless you own a farm, this isn’t the greeting for you.
2.”Greetings.” This sounds too much like something the disciple Paul would say in his letters.
3.”Hey, you.” Saying “you” implies that you forgot their name. Drop the you, and they might be fooled.
4.”What’s crackalackin?” No. Just No.
5.”Wassup?” The 90’s have been over for more than 10 years now. Let it go.