Syndicate and Ultima Underworld have returned to GOG. The classics and their sequels were removed from the service back in June for unclear reasons, but are back now and for the "foreseeable future." Better still, they're all free to keep if you grab them anytime during the next four weeks.
The games were originally removed from GOG by "publisher request", the publisher being EA. There was no reason given for the removal. "It seems that twenty years on there’s still plenty of love for these titles so we’re pleased to confirm that effective immediately they’ll be available again on GOG, and we’ll be keeping them in the store for the foreseeable future," a statement from EA said as part of the announcement of their return. "To celebrate this we’re offering these games as a free download for four weeks."
I've never played the Ultima series, but Syndicate was a formative illicit thrill when I was a kid. I think the only thing I ever did in it was take pot shots at police cars, then steal the police cars, then use them to run over women with prams. This might be why I've yet to tell my own kid that videogames exist.
Would I recommend you play any of these games in the here and now? Probably not! They're historically interesting and I am glad that they are both available outside of EA's Origin, but there are a lot of games to be playing, aren't there? Six or seven, at least.