which unix shell is best?

I still use tcsh, even now that I'm off the BSDs and onto Debian (laptop, sigh). I like the syntax, I like the way it behaves, and, more importantly, I already have my .cshrc just the way I want it, and I'll be damned if I'm going to spend the hour or two it'd take to port it over to bash. I'll also never give up vi! I used zsh for a while, and it wasn't bad, but I didn't get particularly attached to any of it's features. And I'll echo everything everyone has said about shell scripting... aside from a little bit of sh scripting, and my .*rc files, I've never touched it - if it's a one-liner, tcsh + awk/sed/xargs will do fine. If it's more than that, perl is your friend.

#!/bin/bash

bash. bash. bash. (bonk on the head), bash. 20 years ago t?csh was cool, a nice improvement over the standard /bin/sh. Every cool person used it. Not anymore, bash, bash, bash... I fight the urge to smack t?csh users upside the head with a dead fish almost every day. No serious geek would use anything else. Use t?csh/zsh/ksh for personal use if it pleases you, but the world runs on bash/sh... (and Perl 5.6.1 or 5.8.3 depending on OS). t?csh is for greybeard sandal wearing old-timer people... bash, bash, bash...

Bash seems to be winning the popularity contest these days, but it's been a long time since I've used a machine that didn't have both a bash-like and C shell. So I don't think there's any reason for you to change if you don't want to. Personally, I prefer ksh, but I don't have a ton of real arguments for its superiority over bash; I just have always used it and don't have any compelling reasons to change.

I used to know that scripting-wise, it was best to write for a standard shell that you could be confident would be present on almost any system your script ended up on, which generally meant a sort of POSIX compliant shell, usually bin/sh. For personal interactive-command stuff, you picked whatever you felt comfortable with. As a sysadmin, I tried to stick with whatever the default was, so I'd notice problems before the users did. I don't know what the kids are using these days. Probably some combination of Ruby and a Wii controller.

I use zsh for interactive/command-line, and made the transition from tcsh to bash to zsh years ago. Completion, globbing, etc. There are plenty of sample dotfiles for zsh, too. But I don't script with the shell: the most I'll do are loops through lists of files.

I'm quite happy with tcsh aside from a few niggles I'm sure you're familiar with. It's a highly underrated interactive shell, even if it's crap for scripting (but then, so are all the other shell scripting languages, urgh). Programmable completion, plenty of configuration options, decent usability.. I don't really think I'd gain much switching to zsh (except I'd have to install it myself in a lot of places) or bash (except I'd have to port all my existing settings). The crap stderr handling I encounter rarely enough that I can just drop into sh if I really need to get around it. Really, I've used bash and zsh. The things I liked about them I found I could usually do just as well in tcsh, and it comes in the base system for most of my systems, so why not use it? I like learning new things too, but new shells don't seem to be a particularly good use of my time.

I was hard core tcsh user, as it was the first I learnt. But if you do scripts, you tend to always use "sh" to be compatible. (yes, sh, not bash! Stop assuming it's bash linuxers! I'm looking at you!) So I ended up "having to know" both bash style and tcsh style, ways of doing things. (foreach vs for and all that). So just using bash made it easier, and made me be better at making the scripts. Once I made the prompts look the same, it was no difference. Then I discovered a couple of bonus features, I really love ^R now (like emacs, search backwards in history), and I found UTF-8 (Japanese) to work more easily in bash. But really either shell is fine to use, it was just easier to use/memorise just one subset.

jeffamaphone-I prefer PowerShell. The OP said he's using Mac OS X and various Linux/Unixes. PowerShell is totally irrelevant for his needs, since it does not run on anything but Windows. SpecialK-My suspicion is that since /etc/rc and cronrc files and other base system shell scripts *MUST* be written in bash, tcsh and csh have fallen into disuse as switching syntaxes all the time can cause some serious problems in absent-minded sysadmins' heads... not to mention their systems. Actually, base system shell scripts are usually executed with whatever the system's default is for /bin/sh. That is usually bash these days, but for instance, Ubuntu uses dash, not bash. Best practice is to avoid "bashisms", and write your base system shell scripts as POSIX shell scripts that will work no matter what the system's default shell.