The best rubber suit monster movie from the 1950s is probably The Thing From Another World, but probably the most popular is Creature From the Black Lagoon. I'm not altogether sure why it doesn't look as cheesy today as so many of its lesser kin. Perhaps it is because the look of the creature is a little more plausible than most rubber suited monsters; more likely because it is seen in part as a sympathetic character rather than a one-dimensional horror. The filmmakers clearly know how to play off the natural human fear of the unknown, in scenes where the characters swim unwittingly close to peril, and the underwater cinematography is fantastic. This is not a great film, by any means, but it's great pulp and a lot of fun.