The original Dungeons and Dragons was about killing things and taking their stuff.
Here are generators and tables for that stuff, as well as character trinkets, magic weapons and dragon hoards
Disclaimer. I'm an affiliate for DM's Guild and I also create a lot of products with random tables on DM's Guild..
Redkat's Treasure Generator has more detail on the items and art and includes a variety of mundane items.
For an option without magic items, 5th DnD's treasure tool returns 4 sizes of loot at once, from "minor personal loot" to "treasure hoard".
Donjon has a magic item generator with filters by rarity and type.
A variety of weird magic items can be found, from potions of gelatinous transformation to the prismatic blade.
And last is a generator for drawing cards from a deck of many things...
For individuals then take a look at the individual monster tables of Lady Tiefling for Giants, Hags and everything else D&D
Or for pickpockets, hobbit riddles and mundane loot try items in an NPC's pockets
5E has DM's Guild and on there you can find tables with Loot and Fortune with tables for mundane and different monster types.
For a different type of looting try Hamund's Harvesting Handbook, with rules for harvesting from monsters and creating things from them.
I'll keep this guide updated so please suggest generators in the comments or on my Discord server