Unusual street captures... those keeper moments you get only when you are least expecting them!
Crazy colors (I love toy cameras)!
Angles (when appropriate... it's hard to explain).
Off centered subject matter.
crap in the name of street photography (who cares about a dumpster in the alleyway anyway).
boring poses (once again, it's hard to explain)
Just want to make a note that, some people can make even the flowers and birds and those dumpsters look pretty cool somehow... I've seen them. So in general, I don't really think there's a rule to what is a turn on or what is a turn off... it's all contextual...