I find I'm happiest working in a language that allows very easy integration with C, but provides garbage collection, some kind of module system, better strings, a REPL, etc. You have more flexibility while prototyping, but can rewrite the parts in C that need it, and all system calls (fork, dup2, etc.) are still accessible. Having a pervasive associative array ("dict" or "table") type in the language helps, too - it's an incredibly versatile data structure.
Lua works particularly well for this (and it's simple and clean, like C), though Python and Lisps/Schemes that compile to C work well too. (I can't vouch for Ruby here, since I already know Python and Lua and haven't bothered with it.)
See also: Andrew Koenig's "C Traps and Pitfalls" (http://www.literateprogramming.com/ctraps.pdf) and the book, which expands on the paper.
So basically if you want to create a large project in C you have to build a number of intermediate layers (otherwise the code will be a complete mess full of bugs and 10 times bigger than required).
This continue design exercise of creating additional layers is the hard part about C. You have to get very good at understanding when to write a function or not, when to create a layer of abstraction, and when it's worth to generalize or when it is an overkill.
Of course the same thing happens in other languages as well, and even in higher level languages, but usually in C there are more layers of abstractions required compared to a similarly complex project written in an higher level language.
Another difference with higher level languages is that with C the abstraction layers at the "bottom" usually have to deal with low level details that require some practice and knowledge. For instance it's common to implement data structures, some automatic memory management stuff like reference counting and so forth.
This is the reason why I think programmers should learn C and try to write at least a large project with it: it's a good exercise.
C just starts requiring these layers at a slightly earlier point in the abstraction continuum. On the other hand, the low-level abstractions are the easy ones: my experiences verify that in a medium-size project and up, with C you will have quickly built your own vocabulary and primitives and you get to the meat only a bit later than with some higher-level language.
I don't mean that C is all you need but that it's not the big problem in practice. I've seen so many large C projects where most of the code is about the problem domain itself and only a minor part is dedicated to overcome the C's lack of features and primitives.
I somehow recognize it as a good thing in C, forcing the programmer to build these layers early. You'll have to do that eventually and if you're so used to doing it already, you'll have more brain left for the actual problem itself.