I am looking for a relatively large PGN-formatted database (with at least 500k+ games), that is downloadable, with possibly the following properties:
Few such, but very small (2-3 thousand games) databases can be found here.
It would be preferential if the database was diverse, for example not being only composed of man vs. machine games or somesuch. No real constraint on the ratings, whether the levels (amateur to super grandmaster) are fairly balanced or whether it's a 2000+ rating database.
Although a single-file database would be easiest to work with, say for parsing purposes, one that is divided onto multiple PGN files would also be perfectly fine, as long as they were formatted similarly and did not contain too many duplicates.
In other posts, one mentioned database with similar properties to the above is the ICOFY database, but unfortunately it does not seem to be maintained any longer, nor can a trustworthy download link for it be found.