Solaris... yes... it is a better film, I wonder how many ten year olds could sit through it though, and of those that could how many would understand or enjoy it? But that is a digression, ten year old enjoyment does not make a movie science fiction.
However, I never did feel that Solaris was actually science fiction though. It was more a movie about regret, remembrance and guilt. Sure it was set in space, but that really was just a plot device, the Solaris effect could have been a mysterious planet or a mysterious crystal, or a potion, or session of hypnosis. This was not science fiction in the true sense of the word, there were no science bits.
Of course you can say the same about Star Wars, which I believe was originally a serial set during the second world war. Star Trek I think just makes it into the category of science fiction, Close encounters, certainly, Superman is another opera. Blade Runner was a potential science fiction you missed, but that's more dystopic than science based.