It seems to be a list of "classics" more than necessarily a list of good books or good scifi books.

I'd put Andromeda Strain on there before Timeline or Down and Out.

It's funny that Down and Out is one of the few modern books on there - it's more notable for the buzz around its distribution than being any good.

A lot of these books are really, really dated. It doesn't mean that they shouldn't be on your must-read sci-fi list.

And 20,000 Leagues is so 1870's. ;)