“Geesum Pete” is a common one in southern Louisiana—maybe the South in general. I don’t use it, but I have a soft spot for it.
My aunt says “Aww sugar,” which is also amusing.
Once, I heard a female college tour guide use “Oh my flip,” which still seemed pretty inappropriate, because it was impossible not to fill in your own translation.
Oh, wow… I almost forgot the best one. I was buying something at a ghetto Circle K and the large, black lady behind the counter was taking her time ringing up my sale. She brought me my debit receipt, but no pen. I was being kind of an impatient dick and said sort of sternly that I needed a pen. I guess she ddn’t want to do too many things at once, because she walked back over to where my receipt came out to get the pen and then walked back over to me. I signed and said “thank you” somewhat artificially, I suppose to which she deadpan replied as I turned to walk out the door “Merry Christmas.” It was July. She just told me to go fuck myself. When I realized that later, I thought it was freakin’ hilarious. I wish I had thought to wish her a Happy New Year.