these may seem typical, but the first actor i ever was really obsessed with was Lee Jong Suk and i still love him a lot as well as Kim Woo Bin (woo bin has a great personality that works well in dramas/movies/etc). I actually like a TON of male actors but Jongsuk and Woobin are the only ones i particularly pay a lot of attention to these days.
i don’t really have a favorite actress but from the dramas i’ve watched, i’m quite fond of Lee Bo Young, Park Shin Hye, and Gianna Jun.