Story

If you don't need quite all the bash-isms, mksh is a great lightweight replacement, which is almost entirely drop-in compatible:

* http://mirbsd.de/mksh

I prefer mksh primarily because bash goes horribly brain-dead when you attempt line-editing on command lines that wrap-around to the next line. Your bash session becomes practically unusable after you hit that limit (which I do, often) and it first wigs-out:

* http://i.imgur.com/Vo2BQq2.png

It doesn't hurt that the mksh binary is 3.4X smaller, starts-up faster, is more responsive, can be statically linked, and doesn't hold open 28 files, all of which matters a lot in a minimal system recovery type situation.