1) I used to work at Radio Shack. Anyone in Consumer Electronics Retail can commiserate with me. Old people that buy electronics -- If you think I'm talking about you, you're wrong. You have a computer and were most likely able to find the on switch without too much personal assistance. If you're too dumb to read the instructions, don't buy it
2) People who have a high sense of entitlement. Thinking the government or other people will always provide for them. If I see a panhandler, I'm tempted to kick the guy in the teeth. There are folks that are unemployable, but I've really never seen those folks out begging for $.
3) American tourists... I am one, but I'm talking about the typical American tourists. White socks and sneakers, can be picked out of a crowd overseas with great ease. They go to Spain and expect enchiladas and nachos.