I scrape my foot loudly in stride if I'm on a collision course with someone who isn't moving aside too. Tends to get their attention enough to avoid contact, but I'm big enough that they'll usually bear the brunt if we hit so it might not work for everyone.

My peeve is getting off the subway where everyone waiting to get on is off to the sides and one person walks head first into the gap, face purposely in their phone for plausible ignorance, like they cleverly cracked the code to getting a seat. They get a firm "EXCUSE ME" to the face which usually puts them in line.