Which is hottest; chili, mustard, curry or wasabi?

The Red Savina Habenero pepper with at 577,000 Scoville units

http://answers.google.com/answers/threadview/id/332910.html

The hottest pepper is the Bhut Jolokia, at 1,001,304 Scoville Heat Units(ghost chili). So you could make your chili with that, I wouldn't recommend it though.
https://www.ufseeds.com/on/demandware.store/Sites-UrbanFarmer-Site/default/Search-UpdateGrid?cgid=super-hot-peppers&srule=Featured&start=0&sz=12

Curry is a generic term, a lot of the heat comes from peppers. So, you could make an equally hot curry with the above pepper.
https://en.wikipedia.org/wiki/Curry

Wasabi and mustard are from the same family. Real wasabi isn't too hot, and the wasabi that most people have tried is a mix of mustard seeds, horseradish, and food colouring! Black mustard seeds are the hottest.
http://www.realwasabi.com/News/index.asp

The heat from peppers and mustard attack different areas, chili goes for the throat and tongue, mustard goes for the nasal passage, so they can't be compared like for like.