I recently tried using an alternate xubuntu install to do a minimal command line install and then just installed bits and bobs, but some of the tutorials I found didn't seem to work, and so I had to mix and match bits from various places to try to get xorg to work properly for xwindows. But it didn't seem to good.
So I installed Ubuntulite
http://ubuntulite.tuxfamily.org/ on my old PII450 and it's OK.
before either of those I tried openSUSE 11.0, which run ok using jwm, but did install a lot of bloat. ( I use it on my main PC and like it)
DSL was mentioned earlier and is about as lean and mean as it gets. Puppy Linux is nice to, or there's a few variations of PCLinuxOS, or vector linux.
Those are all aimed at ppl who want an up and running lightweight desktop so may not be what you want.
As mentioned earlier the debian net install from what I've read is a good way to get what you want and may be what I try next if I get unhappy with ubunutlite.
If you want to go hardcore try Slackware or do it from scratch:
http://www.linuxfromscratch.org/ 