I gave CiV 5 a chance. I played it non-stop for months, bought a few of the DLCs, and found it mildly interesting. Then I got bored. One day last fall, I re-played BTS for the first time in over a year and realized just how much better, more complex and intelligent (especially in diplomacy, espionage and religion) it is compared to Civ 5. I haven't played Civ 5 since. So IMO, Civ IV BTS is indeed the "Jewel in the Crown" of the Civ series. At least until a Civ VI ever comes out. Because Civ V (no matter how much they patch it) will never even come close.