At the top of the page here: http://jokermartini.com/welder/ Also: Outliner Monster's Key Tools Monster's Gradient Map Baker JJTools Wrap-it Max Retopo Soulburn Scripts Labyrinth QuadSphere ProTrajectoryHandles ProSequencer aa Stone Wall Placement Tools Rock Generator Fracture Voronoi Primitive Maker Deform Edges Miauu's…
There are tons of useful plugins and scripts, mostly free on scriptspot.com. I always go there when I feel like something could be done easier and faster.
Lately I've been using Neil Blevins' scripts a lot. http://www.neilblevins.com/cg_tools/soulburnscripts/soulburnscripts.htm In addition to Scriptspot, Maxplugins is also helpful for finding things. http://maxplugins.de/
Outside of the graphite tools, WrapIt, and SoulburnScipts, I don't really use much else. Apart from some random situational scripts/plugins from JokerMartini. http://jokermartini.com/products/