Eternal Sunshine of the Spotless Mind (2004) makes the list for its depiction of how memory is stored.
Sensibly, the film depicts memory as essentially a network of links. In its frenetic second half, Joel is asleep while the technicians "operate" on his mind. We follow as he careens from recent memories of his relationship to those of his earliest childhood.
Alien (1979) gets a thumb up for its depiction of the alien's life cycle, despite it's fantastic growth rate.
Every element of the life cycle can be found in nature, variously in parasites, robber wasps and social insects. Much of the film's suspense comes from the filmmakers' decision to let events unfold without too much explanation – the viewer has to piece the life cycle together for themselves.
Perennial favorite Gattaca (1997) is included for its "grimly plausible vision of a society dominated by genetic prejudice."
The other two on the list are 2001: A Space Odyssey (1968), for its depiction of space travel and Solaris (1972, 2002) for its "portrayal of the limits of science and of human understanding."
The great thing about all these movies is not just that (at least some) of the science they depict is plausible, but that they are entertaining. There is no reason why the science has to be awful to make a good movie.
Tags:science fiction, biology, Eternal Sunshine of the Spotless Mind, Alien, Gattaca, movies