The Joker best man storyline has some of King's best dialogue, not surprising given that religion seems to come as naturally to him as romance. He really does his strongest work in those areas.
"The Gift" is, well, frustrating. The opening with Green Lantern is so twisted and memorable that it deserves a better story. Booster had just lectured Superman in Action Comics about not making changes to the timeline, which is hard to reconcile with his behavior here. Also, there have been so many good alternate reality/ dream sequence stories where Bruce's parents survived and this doesn't measure up to 99% of them. On the plus side, they fit in Catwoman's look from Batman Returns.
The wedding issue is pretty good if you completely overlook the absurdity of all this stuff coming together exactly as planned. Selina's fiercely independent so it's perfectly conceivable that she wouldn't make Batman's continued existence her primary concern or that she'd still be pissed with Holly about damn near killing Bruce. But this isn't a King thing, it's fiction across the board these days. All the evil plots involve villains knowing exactly how every person will react to any given situation without any deviation until the very end.