For an iconic genre example, The Lost Skeleton of Cadavra (2001) is very hard to beat. Nearly pitch-perfect, it is a spoof of those science-fiction films from decades ago, locking on to everything from the shaky science they depended on to the unbalanced social roles they promoted, from the bad acting to the nonsensical plots. Speaking of, this plot can only be barely described as a tug of war over a rare and useful new element. Keep an eye out for the strings used to manipulate the skeleton.
There are parts which you may not like, but if spoofs are your reason for existence, then make sure you see this one!