Well rip off or plagiarism are the disparaging names,
you can also call them remakes or "hommages".
Remakes often have the same name as the original and credit the original author so there is no point of calling them plagiarism. Plus there are way too many to list here (dozens every year)..
Movies that look like a foreign films that they do not credit are also frequent, though it can be through "inspiration" or the original film was not so original in the first place.
Magnificent seven is an uncredited remake of seven samurai, but even then it is the small story, since the same plot idea has been used in countless other movies, and actually even the parody version created a sub-genre (used in "galaxy quest", "a bug's life", "three amigos", etc.).
Reservoir dog is largely inspired by City on Fire, but Tarantino has said several time, that though he recognizes his influences will not credit the movies he copies.
The lion king, though looking like an original idea (people will say it's a rip off from Kimba the lion, which is denied by Disney), the story is actually inspired by the one of Hamlet.
The ending of The Recruit looks terribly similar to the end of LA confidential, but the same plot mechanism has probably already be used in countless other movies.
LeGreg