I can't say I'm one for using a lot of plugs, I like to find them, go, "dude, that rocks! I need that." download them, then leave them sitting zipped in a folder till I've forgotten I even have them or what they're supposed to do, and end up never using them, but there are a few I do have installed and do use from time to time or regularly.
I've got a couple of the "PLG" plugs installed. They're great for UV'ing,
ONLY if you've already got a good grasp on UVing, and seam placement, definitely speeds the process up a bit. For those interested...
PLG Plugins...
Polygon Coloring; a must have for rendering subpatched wireframes. I'm not sure there's really a better way to do it.
Polygon Coloring...
Merge TirgonsX; Attempts to convert a tripled mesh into a quad mesh, does a pretty fair job, useful mostly for importing meshes going between software, and low poly work. [Can't seem to track this one down, its older tho I believe, and there's a host of newer ones that do the same thing, possibly better, listed on Flay.]
Last group of plug-ins I use, are some normal mapping ones. They can be found, with a small tutorial at the attached link, and I think they're used in the free normal mapping tutorial video on Simply as well. Again, they're older, and I'm not at all sure of their compatibility with v[]9.
Normal Mapping...
One more I want to mention, tho I don't use because I've had some stability issues with them, which I have little doubt is specific to my computer and I know a few people that do use them without problem, is Dennis Pontonnier's Renderman ports.
Renderman Collection
That's my rundown, on the "greatest plugins eva!" Don't use too many, but the ones I do, are there for good reason. I even posted links to most of them for ya, aren't I nice? :p
Cheers guys. :beer: