Favorite portable; without a doubt - Cambridge Z88. So slick, SO portable!
Uppgradable to 512Kb internal memory, 4MB in total, Flashcards available (or build your own).
A remarkable little machine. New in stock from resellers _today_ both in the UK and US. I got mine for free from a friend who bought it at a flee market for a few bucks with 128k RAM and 32k EPROM.
Also take a look at the Amstrad NC-100, I think it's pretty similar. I also have an Osborne 1, but it's currently out of order. Working on that... Bad RAM I think
Outbound laptop/notebook: Motorola 68000 Macintosh clone. Lots of unique things about it. When it was released in 1989 it required a Macintosh SE or Plus ROM in order to fully boot. While this may have been a turn-off to some who were looking for a true Macintosh laptop it's nearly $4000 price tag made it appealing when you consider the "luggable" Macintosh Portable was nearly $7000. If you needed your donor Mac working again, simple plug a cable from your laptop into it. It also had a horizontal scroll bar as a pointing device, something I've yet to see on any other portable computer.