Here's a weird one.
I was only born about a week after Star Wars was first released, so I didn't actually see it until Empire came around - our local cinema (like many, I'm sure) was showing the pair as a double bill, so that was my first exposure to the saga (a pretty intensive one, I guess!)
Anyway, I VIVIDLY recall Empire having a completely different title sequence from Star Wars - no crawl, no big theme, just photos of the characters with their names, underscored with some fairly tranquil music.
Retrospectively, I can just about rationalise it with the assumption that the cinema showed the Empire trailer directly after Star Wars, before the intermission - the main trailer certainly does have stills of the characters appearing amidst the live-action footage. But still, that's not really what I remember...
Like I say, weird! And it looks pretty absurd in writing, but I thought I'd share anyway...