It would be nice to have all that games in a database, but only if it would be available to all lichess players. Perhaps a database dump every month (that would probably mean about 50Mb in Games) And yes, scid would be nice or just a pgn dump compressed./ Having a single button to have mailed your own games would be nice, too.
I only found 2 posts on this subject and from what I understand there is still no way to download your own games in a PGN file? the only thing I see at the top of my profile is the Export games button, what am I supposed to do with the CSV file? I open it in notepad and it doesnt look like it would translate into PGN so am I supposed to see my games with this? If not what is it for?
After you got all of the game IDs, to download all of the games would be a relatively simple task; you would simply prepend "http://lichess.org/" and append "/pgn" to each game ID, and then save the response to a database.
Oops...it appears that thibault has placed a cap on the number of games you can call up from that page...and several other pages, preventing you from retrieving all of the game IDs.
The only other way I can think of to get the game IDs would be to get the top 1960 players from the "people" page (maximum thibault has allowed), and "export games" for each one of them. This still would not get you all of the games but it would get you many of them, since the top players are the ones who play the most.