Who made the last one with a decent line out?

While the word "decent" is subject to debate the current Sony D-EJ2000 has a decent "true" line out.

Sony 1998... D-E905 ~ good luck with finding one
Sony 1997... D465 ~ pretty good, and easy to find
Sony 1995... D777 ~ talked about to death here... commands a high price
Sony 1992... D311 & D515... the epitomy of Sony line-outs? both end up with a bidding war on ebay
Sony 1991... D303 ~ arguably the best line out of any Sony Discman period???

I could go on, and... being a bit of a Sony person am a little bit prejudiced...

The E905, D465 (moreso) and D777 all have shock protection and can use either AA batteries and the D777 / E905 also can use gumsticks for extra usage time...

All the rest are to all intents and purposes deskbound due to having no shock protection...

As to other manufacturers... sorry, I don't know at the moment

iRiver still makes units with a line out... whether it's a true line out or max'd volume is subject to debate (or not). Also lots of off-brand makes have line out (RCA, Electrohome, etc.)

Of the big brands, only the high end Sony has one (North American releases, anyway.)