I feel validated that the chaining comparison operators feature is #1 in terms of votes (303 vs #2 at 249 as I write this). Nobody else seems to think it worth mentioning, but chaining comparison operators is a feature I'm really fond of in Lisp/Scheme: http://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node124.html
I wouldn't say Lisp has chaining of comparisons, only chaining of identical comparisons: a < b < c --> (< a b c), but a < b <= c --> (and (< a b) (<= b c))