I loved "Cloverfield"-actually I enjoyed the "absence" of of seeing the creature for most of the shots. It added an intensity to the mystery for me. When we do see it, it looks awesome I can't wait for Super 8, too.
My favorite creature features are Giant Spider Invasion, Kingdom of the Spiders, Deep Blue Sea, Leviathan, Deep Star Six, Jaws, etc...
I haven't seen many of the older giant monster films... I watched some, like the one with giant ants that's in black and white that I can't think of the name of... lol.
I also liked King Kong (and remake) and Godzilla (but not the remake).
As I've said elsewhere on this forum, my favourite Sci-fi film "This Island Earth", features 2 kinds of creatures - the inhabitants of Metaluna 3 - who just look like humans with very large foreheads, and the fantastic Mutants that also come from that planet and are used as slaves. Although they are only man sized, I think they are pretty impressive for the year the movie was made - 1955. They only appear in about the last 10 minutes of the film though!