A few thoughts: Raquel Welch in a cave bikini and dinosaur stop motion by Ray Harryhausen? I'm not exaggerating when I say this is one of the best combinations of two things I could possibly imagine for a mid-'60s caveman movie. Choosing to have its characters not speak in recognizable language and instead get their points across through visuals was a pretty bold move. Yes, it's been done in other movies, but that doesn't make it any less admirable. The plot is loose and incredibly thin, and you can tell it's basically just designed as a method to give us Raquel Welch in a bikini and show off some awesome dinosaurs, but I'm kind of alright with that. It's fun in an exploitative kind of way. Director Don Chaffey had done better before (Jason And The Argonauts is an all-time favorite of mine), but I still can't see anyone else handling this material any better. It's very simple in a lot of ways, however the execution of the ideas and set pieces definitely should not be so easily dismissed. But in the end, it is definitely more iconic than it is great.
Who would I recommend it to? Mostly this movie has two things going for it: Raquel Welch and Ray Harryhausen. It doesn't disappoint on either front. Watch it if you want to see those things.