A number of assets from the store made creating my games much less time-consuming than it would have been otherwise. I'm not being paid or otherwise incentivized to list the following - this info is provided for other game devs to satisfy curiosity and possibly be helpful in case they might need something similar. I'm also not listing resources / other websites at this time (for example freesound.org), although I may create a different page for that sort of thing in the future.
Rewired. This is an input framework, which among other benefits like native input on some platforms also makes creating control remapping and other input-related systems much easier to code.
Procedural Primitives. Makes it simple to generate lots of different basic shapes of meshes, with custom vertex density etc. at runtime or in edit mode.
Asset Usage Detector. This free developer tool finds references to assets (for example, if your game's build has a specific texture file included that shouldn't be there taking up space etc., this makes it easy to track down why). Has helped solve a number of mysteries over the years! Indispensible.
DinoFracture. A mesh fracturing framework, used extensively while creating Tower Offense.
Mesh Deformer. I use this to create curved geometry like the sidewalk-type walls in tunnels of Rural.
Broccoli Tree Creator. A foliage creation system which includes a number of different 3D trees. I use this to generate them procedurally at runtime when a world initializes, to avoid having the additional download/storage size overhead (although for WebGL builds, I default to 2D trees for performance, but 3D may be enabled in the in-game options).
Auto Fence & Wall Builder. Includes a ton of different fences and walls meshes and textures along with a placement tool.
River Auto Material. I use the spline mesh generation capabilities of this throughout Casual Racing for road surfacing (combined with additional processing after generating, to split into chunks and align to surfaces for the more offroad-type routes), also the river and lake in the Rural world use it (but worth noting that I haven't spent any time configuring that to look good, as it's hardly ever visible / just background scenery in some camera angles briefly).
AllSky. Currently 220+ included skyboxes makes this a bargain for sure. I've used quite a few, along with my own system for blending between day/night skyboxes (based on time of day) and details like a moon and animated stars.
Elven Assassin. I used this free model in "Bagged!" and some public tests/demos including my taxi thing (which is no longer available to play - was a prototype released briefly).
Inverse Kinematics. A simple and free IK solver, used for the character's arms and legs in "Bagged!".
Several other assets I've used are not listed, because either 1) they required so many changes, needed critical bugs fixed after importing or basically needed to be rewritten entirely for whatever reason, in which case I can't recommend, or 2) they're things of subjective value only, like textures, rock packs, etc. where you'd pick something that fits the style you're going for and performance budget, or 3) they didn't come to mind at the moment, but I'll eventually add them to this list.
There are also quite a few assets I'm not listing despite being quite fond of because they weren't used in any of the titles I've shared so far. They'll be added here once they have been :).
Also worth noting, for poor people like me, I rarely pay the full/listed price - assets often go on sale, so if it's not urgent, you may want to wait until the next time they're available at a discounted price (which is often for 50% or less) or become available as part of a Humble Bundle etc.
I'll eventually get around to adding a contact form here, but feel free to send a private message on Unity Forums for chat or email address. As this website is mostly only known by other developers at the moment, alternatives are low priority.