Haven't seen neither The Big Heat nor Young Frankenstein up to now, but Karloff's Frankenstein is a true gem and Whale is a master of his craft. It's (by far) my favorite of all these horror films. I do read often that The Bride is supposed to be even better, but I disagree, while it's a great movie nevertheless. The scene where: SPOILER the father took his dead daughter into the celebrating village, is breathtaking imho and strongly reminds me on the 'coffin' scene in Vampyr END SPOILER
With these movies, I always try to imagine how it must have been when people saw it for the first time back in the 30s. Which one do you actually prefer?
I am still searching for The Son of Frankenstein with Rathbone. Hard to find a copy here.
Although they all are associated with the horror genre, it's more of a showcase of philosophical and psychological themes and motives. Great stuff!
You haven't seen "Young Frankenstein!!! Oh, shame, shame...you must see it!
"Bride Of Frankenstein" (as well as "The Invisible Man" - also directed by Whales) employed some humor. Shakespeare thought humor heightened the impact of drama, so there is a good history for the concept. I prefer the original "Frankenstein"..as you can tell from my avatar. The classic movie station TCM ran "Bride..." and "Son of..." after the original. They're both very good, and worth seeing, but I still prefer the original.
The version with Rathbone is OK, but not up to the original. Karloff's subtlety, even in that unforgiving makeup, (which he helped design) was remarkable.
The picture below is from "Bride of...". I have it framed on my wall...