The Best Logique Evidence of God Existence

[vulcanlogician]

The principle of sufficient reason is compelling enough to illicit concern over the first cause. This doesn't mean one must conclude "God"... but, hey, it asks a pretty good question: Why does all this shit exist? True, "Godidit" is a poor answer. But still. There's an unanswered question floating about.

What about, ‘things exist because there’s no logical alternative’?  Or, said another way, ‘existence is necessary.’  Would that qualify as a ‘reason’ according to the PSR?

Yes. That is a perfectly valid way of approaching the PSR. Things that exist, exist because they must exist. It is necessary for them to exist.