Hopefully, the editor of the passages will chime in because he/she did good job providing 2 sizes per clip.

I'm not sure if the consensus is that Windows Media Video format is best, but whether you like Microsoft or not the WMV format seems to create decent video with the smallest foot print.  And WMV can be run on Macs.  I'm not sure about Linux.

Audio Codec: Windows Media Audio 9.1
64 kbps, 44 kHz, stereo (A/V) 1-pass CBR

Video Codec: Windows Media Video 9

Bit Rate: 512 Kbps

Video Size: 320 x 240

The Dial-up is:

Audio Codec: Windows Media Audio 9.1
8 kbps,  8 kHz, mono (A/V) 1-pass CBR

Video Codec: Windows Media Video 9

Bit Rate: 38 Kbps

Video Size: 160 x 120

I've used Real Media Video on some of my videos because people were saying that the version of the Windows Media Video codec was not yet available on the Mac.  However, I have heard that it is available now.

I've avoided MPEG because they are HUGE.  Maybe I don't have the right software, but the size could be 2,3 or even 10 times the size of WMV.  However, someone said that there are compression utilities available (e.g. Sorenson Squeeze at $500 USD) that does a pretty good job, but my budget just couldn't handle that expense.

I think that from now on I'm going to try the aforementioned settings.  They seem quite adequate.

And kudos to the editor of the re-mastered Passage Video clips.  Great job.