I really enjoyed Sinestro Corps War - it was what I would consider a manageable-sized event. (Final Crisis I would call an unmanageably large size event). Consists of 3 collections - don't forget the "Tales of the Sinestro Corps" collection - That Lyssa Drax is a hottie.
I don't remember rightly which one goes first but if you get interested in Superboy Prime then you should definitely check out "Final Crisis: Legion of 3 Worlds" (where you can pretty safely ignore the Final Crisis part of the title - it has almost nothing to do with Final Crisis).
Blackest Night is a just a little too big for me to keep it all straight for me. I think I count about 7 collections in Blackest Night (the main title, GL, GLC, Rise of the Black Lanterns, Tales of the Corps, and Black Lantern Corps - Parts 1 & 2). That's way too much stuff. Almost too much to handle.