In my opinion, the Pacifier Prep School ( JAV vids that start with KV-, like KV-243 ) are the best, they let the girls do all the work, without forcing them, and the focus is mostly on the girls, the dudes are amateurs that they pay like 10$ and ask them to not jerk off for a month so their loads are natural and good, sometimes they cum even 2 or 3 times.
You can find some scenes online, but in low quality, the 1080p releases are rare to find because the stupid japs that run this series are crazy racist and make it hard as fuck for Westerns to buy it, if you do have a premium RapidShare acc or some other site, you can get them in the comment section from JAVLIB.
The format is great, it's a girl who slowly sucks someone off, and when they cum she sucks them for a while longer, with POV shots and other angles. And for those who like that amateur-vibe, at the end of most of them, when the girl is on her casual clothes ready to leave, they ask them to swallow one last load while on her clothes and all before leaving.
One of the best works was fairly recent, KV-259 with Akari Niimura. Shes a milf mostly known for her booty, but her blowjob skills are insanely good, the way she slowly works on a cock is just magical.
The only bad thing about those, is the censorship, but still better than most Western fellatio-related porn, where the dude is always an obnoxious prick, who cums water at the end, and most of the time they are more focused on beating the girl with some overly aggressive deepthroat, than having their dicks properly sucked.
So, yea, if you wanna see girls swallowing huge loads, check Pacifier Prep School JAV series, the closest Western equivalent is GloryWholeSecrets, but is less intimate and theres that cringy porn talk.