[filiadragongurl]

You can certainly say "I've seen good films recently" but it's very book-sounding... it feels like something's missing. I mean, most of the time if you're going to say something like that you're going to quantify how many. For example "I saw a good film recently" for one, "I've seen some good films recently" for a few, "I've seen a lot of good films recently" for a lot.

I guess the "some" here just makes it sound a little more normal for what your average person would say rather than what a textbook would say. It also helps to give the person you're saying it to an idea of how many films you've seen. I'm also guessing you would want to say different things based on the context of the conversation.

Anyway, point being you *can* say "I've seen good films recently" and have it be grammatically correct, but I don't think I would ever say that to anyone or write it. Does that help?