what I wanted to achieve by making this thread is to be able to look at the most popular/used plug-ins to see the things that are possible with plug-ins
How do you achieve that by asking who the best plugin makers are? Seems you'd be better off asking what are the most popular / best plugins, rather than plugin makers. (and we already have a couple of threads asking that question)
And how do you define "best"? The person who makes the most plugins is not necessarily the best plugin maker.
I dislike using that word, as it's a measure of quality, not quantity, and quality depends on whether the plugin meets your needs or not, and how well it meets your needs (might be an awesome plugin, but if it's incompatible with everything else you have ...). And you can only determine that by having a need for a specific plugin, then looking at what's available.
often you will not even know you need something (or if it's possible at all) until you discover that there is the plugin that does that.
I disagree with this. You should not "need" something based on whether there's a plugin that does it. If you go looking around to see what's out there and get lured by all the bright, shiny objects (ooh, that's cool, I'll have to find a way to use
that in my game), you're going to end up with a game that's a mish-mash of mechanics and not a lot more. The need should come first. Then you should determine if you can do it without plugins. If you can't, you should then try to find a plugin that does what you need, and is compatible with what you already have. And if you can't you should ask for a plugin or a compatibility patch to be written. It may be that you can't find one, and can't get one written, and you'll have to modify your idea to something that's achievable. But at least it's something that fits your game, not a gimmick that you add just so you can use a plugin that impressed you but doesn't really add anything to the experience for the player.