Strangely enough, I've become rather attached to the tcsh. It's got the features I need.

So a *nix shell is way in which you can skin the linux environment ? Tailoring it to your individual needs.
wurzul -- I don't know that you would call what a shell can provide "skinning". You're probably thinking of the X-Windows interface. X uses different window managers to give the user a different look and feel. The shell is the command-line interpreter that you select to use to interact with the OS. People like to use different shells for all sorts of reasons, but many have to do with the options offered in the shell regarding programming the shell for scripting (like how to declare a variable, how to loop, defined environment variables, etc), and general aesthetic qualities (like prompt manipulation, or aliasing techniques).

avdven is correct, though. You should simply play around with each shell till you find one you like. To use a different shell temporarily, just type it's name at the prompt.