Got a couple mods that I've used in the past that seemed to work well. It's up to the group whether we want to use all, some, or none of these, but the ones I'd consider are:
Automation - Allows you to place a chest next to any number of objects (furnaces, trash cans, pretty much anything that produces or processes something) and it will handle whatever that object needs automatically. For example, if you place a chest with copper and coal in it next to a furnace, the furnace will automatically be filled/emptied until all of the resources in the adjacent chest have been used. Definitely more QoL than game-breaking, but it can get a little overpowered when you do things like fill an entire shed with kegs and load them all from a single chest.
Better Sprinklers - Overhauls many of the functions of in-game sprinklers, both in terms of crafting and functionality. Also shows the covered area of sprinklers and scarecrows when they are placed, leaving out any question of coverage. Has some simple-yet-useful parts to it, but can also be completely game-breaking if abused e.g. you can make the default sprinkler cover a 7x7 area if you play with configs (this may be host-only. I'm not sure).
**Also worth noting, this mod has not been updated since late 2017. It still works, but it appears the dev has moved on to other projects.**
EDIT: The mod in the linked state no longer works. However, an update has been posted on another site that makes it work in the current version. Bit of a chore, but still doable if we want it.
Lookup Anything - Essentially loads the wiki into the game. You can select a villager and view your relationship level with them, how they react to various gifts, etc. The same can be done for crops and any other object on the ground.
No Soil Decay* - Simple mod. Tilled ground remains tilled overnight, even if nothing is growing on it.
*There are a couple variations of this mod. I linked the most popular, but I don't actually remember which one(s) I've used.
Scythe Harvesting - As the name suggests, with this mod, you must use your scythe to harvest instead of picking crops by hand. It makes the harvesting process much faster, as you can get 8 (maybe more) crops per swing instead of the usual 1. There are multiple variations of this mod as well. I linked the most recently updated.
UI Info Suite - Has a fair amount of overlap with other mods. However, it does add some other useful things to the UI. Most notable: Time remaining for crops growing/other machines processing, the luck level for the day, and whether or not you can get a recipe from watching TV.
Experience Bars - Shows a series of bars in the corner of the screen that indicate how close you are to leveling in your skills. Overlaps with some other UI mods, though.
PyTK - Doesn't have any functionality on its own, but is required to use some other mods.
MTN - Like PyTK, serves as a toolkit required for some other mods (including the map itself)
Lastly, while not a mod, the SMAPI Compatibility Chart can be useful when looking at mods. It lists all known mods for the game, and whether or not they work in the newest version of Stardew Valley.
If I were taking a minimalist approach, I would probably take Automation, Scythe Harvesting, and UI Info Suite. The rest are useful, but these three probably have the most utility without severely altering the game.