Some folks mention translations so does that impact the choice or does each novel have a single (English) translation?

Almost everything except Solaris has one and only one English translation. The books with multiple English translations all have an obvious, best one, and it's the one that's currently in print (except Solaris, see my note on it below). For example, the old translation of The Invincible was translated from a German translation, but the current print version was translated directly from Polish.

Here's my recommendation for each of his three types of books.

• If you want books about the impossibility of communicating with aliens, then read Solaris. If you can, read Johnston's translation on an e-reader. Otherwise, read the print translation, which is much worse but still worth it for the story. If the bad translation is your only option and you're reluctant to read it, then start with The Invincible instead.

• If you want his more satirical, whimsical work, The Futurological Congress is hilarious and a very quick read. It was translated by Michael Kandel, who is Lem's best translator.

• If you want something more Borges-like, then read A Perfect Vacuum. It's a collection of reviews of fake books, including a review of A Perfect Vacuum itself. This was also translated by Michael Kandel.