I also use "sed" quite often and "awk" is nice if you want to grab columns out of a file. Just last week someone told me the letters in awk stand for the names of the developers (Aho, Weinberger, Kernighan).

I actually have command lines about two lines long that I use to work out things like for example which IP addresses are connected to my machine's SMTP port sorted by number of connections. I just haven't gotten around to writting a script or setting up a shell alias to do it yet.

I played with a perl shell once but it didn't feel right (ie I wasn't used to it yet, years of BASH have me in their grasp). Also the control characters (^U, ^A, ^E, etc) didn't work on the main server I use at work (but did on my desktop). I don't remember the shell name but I think it supported commands something like " ls -1 | s/aaa/bbb/g " and more.