Nadia: The Secret of Blue Water - Episodes 37 to 39

Fortunately, the phrase "too little, too late" does not apply here.
The final battle with Gargoyle! Electra looking increasingly like Ritsuko ... and other incredibly spoiler laden things! The point is that everything was handled exceptionally well and completely satisfactorily. It's just sad that they couldn't have brought the conclusion around sooner.
Nothing really can be said about these episodes other than that they were full of high drama and capped off with a nice little prologue segment that wrapped up everything ... and one of the characters' fates translates from sweet to creepy dependent on cultural setting.
And Ayerton; who'd have thought. He was representative of what was wrong with Nadia though: that at one stage it had forgotten itself.

Nadia: The Secret of Blue Water was a series that had some extremely bright and shining moments but was damaged by its success, with thirteen episodes or thereabouts seemingly inserted just to give a credible amount of time before the stunning finale for the wheels to be set in motion in the background.
With the epilogue provided at the end of the series, one wonders; is the Nadia follow up movie really necessary? Given that I find the basic idea of the plot offensive, I'll just have to go and find out.