To expand on #3: the "present" in the sentence isn't even taking place before the firing squad, that's "many years later". It places the reader in a timeless moment.
I think another opener that's at least as good is "Maman died today. Or yesterday maybe, I don't know" (even though this is misleading w/o the whole context..)
As much as I like Camus's The Stranger, and am not familiar with Marquez, I still agree with coldtea. In a single opening line (when you know nothing of the rest of the book), Marquez places a beginning (seeing ice) an ending (the firing squad), and makes you want to read more to see what happens in between.
Although that line is memorable I don't think it is beautiful - indeed I rather prefer the opening paragraphs of Espedair Street, which you can read on the wiki page:
Edit - having said that, I think the start of The Crow Road is rather good as that immature desire to shock is rather appropriate for Prentice McHoan - but you can't really tell how appropriate that is until you've read more of the book.