- Blocks (71%)
- Lambdas / Procs (57%)
- Mix-ins / Modules (55%)
- Open classes / monkeypatching (53%)
- Duck-typing (53%)
- First-class regexps (49%)
- Metaprogramming (49%)
- Syntactic sugar e.g. val ||= x; array <<>
- Optional parens / English-like readability (44%)
- Object#method_missing (42%)
The mixin approach to inheritance is also quite popular. This lies alongside open classes and monkeypatching. Rubyists really seem to enjoy the ability to manipulate code inside the runtime environment, and we also see metaprogramming not too far down the list.
First class regexps have always been one of my favorites and I was glad to see they fared well. Beyond that, the type system, syntactic sugar, and method_missing were also popular.
I've left the poll open if you'd still like to vote: