This video shows where to find quality and free datasets for LLMs easily.

ARCS Data Sets

https://csr.lanl.gov/data/

Microsoft Datasets

https://www.microsoft.com/en-us/research/tools/?facet%5Bdate%5D%5Bfixed%5D=any&facet%5Btax%5D%5Bmsr-product-type%5D[]=243083&filter_queries%5B%5D=open&pg=1&sort_by=most-relevant

AWS Open Datasets 

https://registry.opendata.aws/

Google Datasets

https://datasetsearch.research.google.com/

PEW Research

https://www.pewresearch.org/search/dataset

Azure Open Datasets

https://azure.microsoft.com/en-us/products/open-datasets