What’s a common “substitute” ingredient that you prefer over the “original”?

Was just giving this some thought as I was making a French onion dip using plain Greek yogurt as the base. I find it so much better than using sour cream. It made me think to ask what other substitute ingredients people find to be the better alternative.

Edit: Thanks for all the replies! Such an informative post so far. I’m taking some notes here, hope others got something out of here as well!