Coming from that background, C and especially C# must seem extremely verbose.
For example (from Wikipedia):
In K, finding the prime numbers from 1 to R is done with [0]:
(!R)@&{&/x!/:2_!x}'!R
(~R∊R∘.×R)/R←1↓ιR
[0]: http://en.wikipedia.org/wiki/K_(programming_language) [1]: http://en.wikipedia.org/wiki/APL_(programming_language)