my $0.02; (Score 1)

slashdot readers strike me as the kind of people who would appreciate Lem's writing the most.

if you haven't read anything by Lem, you owe it to yourself to run to the nearest library or bookstore and get a copy of one of his books.

if you happen to like Matt Groening's Futurama, then you might want to start with Cyberiad or any of the stories involving Ijon Tichy, particularly Futurological Congress

if you're into "more serious" type of SF; if you like Blade Runner or 2001:A Space Odissey, then go with Solaris

if you are the kind of person who is intrigued by the idea of reviews of nonexistent (not-yet-written? ;-) ) books (i am, for one), go for Imaginary Magnitude or One Human Minute

in any case -- read something, you won't regret it!